Packaging Notes

Security Notes

Functionality Added or Changed

RPM packages now create the /var/lib/mysql-files directory, which is now the default value of the secure_file_priv system variable that specifies a directory for import and export operations. (Bug #24709892, Bug #24761774)

Incompatible Change: The secure_file_priv system variable is used to limit the effect of data import and export operations. The following changes have been made to how the server handles this variable:

(Bug #24679907, Bug #24695274, Bug #24707666)

yaSSL was upgraded to version 2.4.2. This upgrade corrects issues with: Potential AES side channel leaks; DSA padding for unusual sizes; the SSL_CTX_load_verify_locations() OpenSSL compatibility function failing to handle long path directory names. (Bug #24512715, Bug #24740291)

Replication: mysqlbinlog --read-from-remote-server log1 log2 was opening a new connection for log2 without freeing the connection used for log1. Thanks to Laurynas Biveinis for the contribution. (Bug #81675, Bug #23540182)

For mysqld_safe, the argument to --malloc-lib now must be one of the directories /usr/lib, /usr/lib64, /usr/lib/i386-linux-gnu, or /usr/lib/x86_64-linux-gnu. In addition, the --mysqld and --mysqld-version options can be used only on the command line and not in an option file. (Bug #24464380)

It was possible to write log files ending with .ini or .cnf that later could be parsed as option files. The general query log and slow query log can no longer be written to a file ending with .ini or .cnf. (Bug #24388753)

Privilege escalation was possible by exploiting the way REPAIR TABLE used temporary files. (Bug #24388746)

Certain internal character-handling functions could fail to handle a too-large character and cause a server exit. (Bug #23296299)

A blank server name in CREATE SERVER statements produced a server exit rather than an error. (Bug #23295288)

The optimizer failed to check a function return value for an area calculation, leading to a server exit. (Bug #23280059)

A prepared statement that used a parameter in the select list of a derived table that was part of a join could cause a server exit. (Bug #22392374, Bug #24380263)

MEDIUMINT columns used in operations with long integer values could result in buffer overflow. (Bug #19984392)

EINTR handling in the client library has been fixed so that interrupted read and write calls are retried. Previously, EINTR was ignored. (Bug #82019, Bug #23703570)

Incompatible Change: For multibyte character sets, LOAD DATA could fail to allocate space correctly and ignore input rows as a result. (Bug #76237, Bug #20683959, Bug #23080148)

References: This issue is a regression of: Bug #14653594.

Replication: When using statement-based or mixed binary logging format with --read-only=ON, it was not possible to modify temporary tables. (Bug #62008, Bug #12818255)

References: See also: Bug #14294223, Bug #16561483.

MySQL Server upgrades performed using RPM packages failed when upgrading from MySQL 5.1 Community to MySQL 5.5 Community or MySQL 5.1 Commercial to MySQL 5.5 Commercial. (Bug #23736787)

A buffer overflow in the regex library was fixed. (Bug #23498283)

Certain arguments to NAME_CONST() could cause a server exit. (Bug #23279858)

Installing MySQL from a yum or zypper repository resulted in /var/log/mysqld.log being created with incorrect user and group permissions. (Bug #21879694, Bug #78512)

If a stored function updated a view for which the view table had a trigger defined that updated another table, it could fail and report an error that an existing table did not exist. (Bug #21142859, Bug #76808)

If an INSTALL PLUGIN statement contained invalid UTF-8 characters in the shared library name, it caused the server to hang (or to raise an assertion in debug builds). (Bug #14653594, Bug #23080148)

Functionality Added or Changed

Bugs Fixed

The version of the tcmalloc library included in MySQL distributions was very old. It has been removed and is no longer included with MySQL. (Bug #80994, Bug #23068660)

Replication: When using row-based replication in a cascading or circular replication setup, where a master is replicating to server 1 which is then replicating to server 2, merge tables were not being correctly applied on server 2. This could cause an unexpected halt on server 2 while server 1 was unaffected. (Bug #17018343)

INSERT with ON DUPLICATE KEY UPDATE and REPLACE on a table with a foreign key constraint defined failed with an incorrect “duplicate entry” error rather than a foreign key constraint violation error. (Bug #23135731)

References: This issue is a regression of: Bug #78853, Bug #22037930.

Setting sort_buffer_size to a very large value could cause some operations to fail with an out-of-memory error. (Bug #22594514)

Several potential buffer overflow issues were corrected. (Bug #21977380, Bug #23187436, Bug #23202778, Bug #23195370, Bug #23202699)

If the CA certificate as given to the --ssl-ca option had an invalid path, yaSSL returned an error message different from OpenSSL. Now both return SSL connection error: SSL_CTX_set_default_verify_paths failed. (Bug #21920657)

Some string functions returned one or a combination of their parameters as their result. If one of the parameters had a non-ASCII character set, the result string had the same character set, resulting in incorrect behavior when an ASCII string was expected. (Bug #18740222)

A null pointer dereference of a parser structure could occur during stored procedure name validation. (Bug #79396, Bug #22286421)

mysqld_multi displayed misleading error messages when it was unable to execute my_print_defaults. (Bug #74636, Bug #19920049)

Security Notes

Bugs Fixed

MySQL client programs now support an --ssl-mode option that enables you to specify the security state of the connection to the server. If the option is not specified, the default value is DISABLED (establish an unencrypted connection). --ssl-mode=REQUIRED can be specified to require a secure connection, or fail if a secure connection cannot be obtained.

These clients support --ssl-mode: mysql, mysqladmin, mysqlcheck, mysqldump, mysqlimport, mysqlshow, mysqlpump, mysqlslap, mysqltest, mysql_upgrade.

For more information, see Command Options for Secure Connections.

InnoDB: Running REPLACE operations on multiple connections resulted in a hang. (Bug #22530768, Bug #79185)

Replication: The test case main.merge failed when the variables binlog_format was set to “ROW,” as the server tried to get information for table creation for a child table before it was opened. With this fix, the server skips getting information for the table in the situation. (Bug #20574550, Bug #75976)

MySQL did not build with GCC 5. (Bug #22680706)

The System-V initialization script for RHEL6 or older failed to enable the mysqld service by default. (Bug #22600974)

Improper host name checking in X509 certificates could permit man-in-the-middle attacks. (Bug #22295186, Bug #22738607)

A boolean mode full-text search caused a segmentation fault. (Bug #22176795)

Concurrent selecting and flushing of a FEDERATED table while killing connections accessing it could result in a server exit. (Bug #21918190)

Executing GRANT PROXY statements after altering the definition of the mysql.user system table could result in a server exit. (Bug #21699037)

Certain error messages included part of the SQL statement that produced them, possibly exposing data. (Bug #21682356)

Character set conversion operations on NULL parameters to prepared statements could cause a server exit. (Bug #18823979)

CREATE TABLE ... SELECT could create a table with a column of type NULL, which when accessed caused a server exit. (Bug #14021323, Bug #23280699)

For INSERT and UPDATE operations that caused FOREIGN KEY constraint violations, errors were reported rather than warnings when the IGNORE keyword was used. (Bug #78853, Bug #22037930)

References: See also: Bug #23135731.

Processlist state information was not updated correctly for LOAD DATA INFILE and could show a state different from executing. (Bug #69375, Bug #16912362)

Functionality Added or Changed

Bugs Fixed

yaSSL was upgraded to version 2.3.9. This upgrade corrects an issue in which yaSSL handled only cases of zero or one leading zeros for the key agreement instead of potentially any number, which in rare cases could cause connections to fail when using DHE cipher suites. (Bug #22361038)

The Valgrind function signature in mysql-test/valgrind.supp was upgraded for Valgrind 3.11. (Bug #22214867)

Replication: When DML invokes a trigger or a stored function that inserts into an AUTO_INCREMENT column, that DML has to be marked as an unsafe statement. If the tables are locked in the transaction prior to the DML statement (for example by using LOCK TABLES), then the DML statement was not being marked as an unsafe statement. The fix ensures that such DML statements are marked correctly as unsafe. (Bug #17047208)

Replication: DROP TABLE statements are regenerated by the server before being written to the binary log. If a table or database name contained a non-regular character, such as non-latin characters, the regenerated statement was using the wrong name, breaking replication. The fix ensures that in such a case the regenerated name is correctly converted back to the original character set. Also during work on this bug, it was discovered that in the rare case that a table or database name contained 64 characters, the server was throwing an assert(M_TBLLEN < 128) assertion. The assertion has been corrected to be less than or equal 128. (Bug #77249, Bug #21205695)

References: See also: Bug #78036, Bug #22261585, Bug #21619371.

Data corruption or a server exit could occur if a stored procedure had a variable declared as TEXT or BLOB and data was copied to that variable using SELECT ... INTO syntax from a TEXT or BLOB column. (Bug #22203532, Bug #22232332, Bug #21941152)

CREATE TEMPORARY TABLE .. SELECT statements involving BIT columns that resulted in a column type redefinition could cause a server exit or an improperly created table. (Bug #21902059)

Added Microsoft Visual Studio 2015 support. Changes include using the native (added in VS 2015) timespec library if it exists, renamed lfind/lsearch and timezone/tzname to avoid redefinition problems, set TMPDIR to "" by default as P_tmpdir no longer exists, deprecated std::hash_map in favor of std::unordered_map, and added Wix Toolset 3.10 support. (Bug #21770366)

References: See also: Bug #21657078.

When an invalid date was supplied to the UNIX_TIMESTAMP() function using the STR_TO_DATE() function, no check was performed before converting it to a timestamp value. (Bug #21564557)

With LOCK TABLES in force, an attempt to open a temporary MERGE table consisting of a view in its list of tables (not the last table in the list) caused a server exit. (Bug #20691429)

For certain prepared statements, the optimizer could transform join conditions such that it used a pointer to a temporary table field that was no longer available after the initial execution. Subsequent executions caused a server exit. (Bug #19941403)

Repeated execution of ALTER TABLE v1 CHECK PARTITION as a prepared statement, where v1 is a view, led to a server exit.

In addition, output for some administrative operations, when they are attempted on a view, changes from “Corrupt” to “Operation failed”. These include ANALYZE TABLE, OPTIMIZE TABLE, and REPAIR TABLE, and ALTER TABLE statements that perform ANALYZE PARTITION, CHECK PARTITION, OPTIMIZE PARTITION, and REPAIR PARTITION operations. (Bug #19817021)

Using systemd to start mysqld failed if configuration files contained multiple datadir lines. Now the last datadir line is used. (Bug #79613, Bug #22361702)

AddressSanitizer compilation errors were silenced. (Bug #75739, Bug #20459338, Bug #75740, Bug #20459363)

Functionality Added or Changed

Bugs Fixed

MySQL Server RPM packages now contain a conflict indicator for MySQL Connector C, such that an error occurs when installing MySQL Server if MySQL Connector C is also installed. To install MySQL Server, remove any MySQL Connector C packages first. (Bug #21900800)

These client programs now support the --enable-cleartext-plugin option: mysqlcheck, mysqldump, mysqlimport, mysqlshow. This option enables the mysql_clear_password cleartext authentication plugin. (See The Cleartext Client-Side Authentication Plugin.) (Bug #21235226)

mysql_upgrade now attempts to print more informative errors than FATAL ERROR: Upgrade failed. (Bug #77803, Bug #21489398)

Performance: Temporary MyISAM tables (unlike normal MyISAM tables) did not use the dynamic row format when they contained VARCHAR columns, resulting in larger temporary files (and more file I/O) than necessary. Dynamic row format now is used, which results in smaller tables that are faster to process. (Bug #13350136, Bug #78840, Bug #22023218)

InnoDB: Altering the letter case of a column introduced an inconsistency between the frm file and data dictionary resulting in a failed CREATE INDEX operation on the altered column. (Bug #20755615)

Possibly unsafe uses of strcpy() in the mysql_plugin command were corrected. (Bug #21977070)

Possible buffer overflow from incorrect use of strcpy() and sprintf() was corrected. (Bug #21973610)

MySQL RPM packages for RHEL5 failed to create the mysql system user. (Bug #21950975)

Concurrent FLUSH PRIVILEGES and REVOKE or GRANT statements could produce a small time window during which invalid memory access to proxy user information could occur, leading to a server exit. (Bug #21602056)

Starting the server with the query_alloc_block_size system variable set to certain negative values on a machine without enough memory could result in out-of-memory errors. (Bug #21503595)

Using UNINSTALL PLUGIN to uninstall the daemon_example plugin could cause a server exit. (Bug #21467458)

FLUSH DES_KEY_FILE failed to reload the DES key file. (Bug #21370329)

A server exit could occur for the second execution of a prepared statement for which an ORDER BY clause referred to a column position. (Bug #20755389)

Repeated execution of a prepared statement could cause a server exit if the default database was changed. (Bug #20447262)

Outer references do not work as arguments to MATCH(), but the server did not properly detect them. Now it does and raises an error. (Bug #20007383)

References: See also: Bug #21140088.

Valgrind errors were produced during row comparator setup. (Bug #19929406)

INSERT DELAYED could cause a server exit for tables partitioned with a character column as the key and for which the expression required a character set conversion. (Bug #19894161)

A server exit could occur when updating a view using an ALL comparison operator on a subquery that selects from an indexed column in the main table. (Bug #19434916)

When a fixed-width row was inserted into a MyISAM temporary table, the entire content of the record buffer was written to the table, including any trailing space contained in VARCHAR columns, the issue being that this trailing space could be uninitialized. This problem has been resolved by insuring that only the bytes actually used to store the VARCHAR (and none extra) are copied and inserted in such cases. (Bug #13389854, Bug #79028, Bug #22123583)

MySQL development RPM packages could fail to install if MySQL Connector/C development RPM packages were installed. (Bug #78815, Bug #22005375)

Functionality Added or Changed

Bugs Fixed

yaSSL was upgraded to version 2.3.8.

Upgrading from older versions fixes a connection-failure issue when used with the thread pool plugin. (Bug #20774956, Bug #21888925)

InnoDB: A data corruption occurred on ARM64. GCC builtins did not issue the correct fences when setting or unsetting the lock word. (Bug #21102971, Bug #76135)

InnoDB: In READ COMMITTED mode, a REPLACE operation on a unique secondary index resulted in a constraint violation. Thanks to Alexey Kopytov for the patch. (Bug #21025880, Bug #76927)

InnoDB: The IBUF_BITMAP_FREE bit indicated that there was more free space in the leaf page than was actually available. (Bug #20796566)

InnoDB: Setting lower_case_table_names=0 on a case-insensitive file system could result in a hang condition when running an INSERT INTO ... SELECT ... FROM tbl_name operation with the wrong tbl_name letter case. An error message is now printed and the server exits when attempting to start the server with --lower_case_table_names=0 on a case-insensitive file system. (Bug #20198490, Bug #75185)

Partitioning: CREATE TABLE statements that used an invalid function in a subpartitioning expression did not always fail gracefully as expected. (Bug #20310212)

Partitioning: ALTER TABLE when executed from a stored procedure did not always work correctly with tables partitioned by RANGE. (Bug #77333, Bug #16613004, Bug #21246891)

Certain subqueries as arguments to PROCEDURE ANALYSE() could cause a server exit. (Bug #21350175)

mysql_ssl_rsa_setup could create an unwanted .rnd file in the data directory. (The file is actually created by openssl, which mysql_ssl_ras_setup invokes. mysql_ssl_rsa_setup now cleans up the file.) (Bug #21335818)

An assertion could be raised due to incorrect error handling if a SELECT ... FOR UPDATE subquery resulted in deadlock and caused a rollback. (Bug #21096444)

Servers linked against yaSSL and compiled with GCC 4.8.2 could fail to respond correctly to connection attempts until several seconds after startup. (Bug #21025377)

For tables with subpartitions, the server could exit due to incorrect error handling during partition pruning if the partition could be identified but not the subpartition. (Bug #20909518)

DELETE could check privileges for the wrong database when table aliases were used. (Bug #20777016)

Within a trigger, use of a cursor that accessed OLD or NEW values from a row could cause a server exit. (Bug #20760261)

Long path name values for some options could lead to stack overflow. (Bug #20376760)

MySQL sometimes produced no warning when it was unable to interpret a character in a given character set. (Bug #20238729)

For MySQL distributions linked against yaSSL, a corrupt client key file could cause clients to exit. (Bug #20168526)

Execution of certain BINLOG statements while temporary tables were open by HANDLER statements could cause a server exit. (Bug #19894987, Bug #20449914)

On Windows, setting query_cache_min_res_unit to too large a value could result in a value of 0 and a subsequent server exit. (Bug #18487951)

RPM installation scripts failed if configuration files contained multiple datadir lines. Now the last datadir line is used. (Bug #77878, Bug #21527467)

For wait events, the Performance Schema uses the CYCLE timer by default, but failed to fall back to a different timer if CYCLE was unavailable. (Bug #77577, Bug #21374104)

Updating VARCHAR and TEXT columns in the same UPDATE statement could produce incorrect results. When a VARCHAR column was assigned to a TEXT column and the VARCHAR column was then set to a different value, the TEXT column's result contained the VARCHAR column's new value. (Bug #77135, Bug #21143080)

mysqladmin -u root -p could exit with a segmentation fault. (Bug #76538, Bug #20802751)

mysqlimport --use-threads did not actually use multiple threads. (Bug #76480, Bug #20772273)

View creation from a UNION failed with a duplicate-column error if a SELECT statement in the UNION other than the first used the same column name multiple times. (Bug #74539, Bug #19886430)

Empty XML elements having the form <element/> were not handled correctly by the LOAD XML statement. (Bug #67542, Bug #16171518)

Security Notes

Bugs Fixed

Security Fix: Due to the LogJam issue (https://weakdh.org/), OpenSSL has changed the Diffie-Hellman key length parameters for openssl-1.0.1n and up. OpenSSL has provided a detailed explanation at http://openssl.org/news/secadv_20150611.txt. To adopt this change in MySQL, the key length used in vio/viosslfactories.c for creating Diffie-Hellman keys has been increased from 512 to 2,048 bits. (Bug #77275, Bug #21221862, Bug #18367167, Bug #21307471, Bug #21449838)

InnoDB: On Unix-like platforms, os_file_create_simple_no_error_handling_func and os_file_create_func opened files in different modes when innodb_flush_method was set to O_DIRECT. (Bug #21113036, Bug #76627)

InnoDB: An assertion was raised when InnoDB attempted to dereference a NULL foreign key object. (Bug #20762798)

InnoDB: An index record was not found on rollback due to inconsistencies in the purge_node_t structure. The inconsistency resulted in warnings and error messages such as “error in sec index entry update”, “unable to purge a record”, and “tried to purge sec index entry not marked for deletion”. (Bug #19138298, Bug #70214, Bug #21126772, Bug #21065746)

The Spencer regex library used for the REGEXP operator could be subject to heap overflow in some circumstances. (Bug #20642505)

A buffer-overflow error could occur for mysqlslap during option parsing. (Bug #20605441)

GROUP BY or ORDER BY on a CHAR(0) NOT NULL column could lead to a server exit. (Bug #19660891)

mysql-systemd-start failed if datadir was set in /etc/my.cnf. (Bug #77357, Bug #21262883)

On OS X 10.10 (Yosemite), mysqld failed to start automatically. The startup item has been replaced with a launchd job, which enables the preference pane checkbox for automatic startup to work again. (Bug #74434, Bug #19858350)

InnoDB; Partitioning: The CREATE_TIME column of the INFORMATION_SCHEMA.TABLES table now shows the correct table creation time for partitioned InnoDB tables. The CREATE_TIME column of the INFORMATION_SCHEMA.PARTITIONS table now shows the correct partition creation time for a partition of partitioned InnoDB tables.

The UPDATE_TIME column of the INFORMATION_SCHEMA.TABLES table now shows when a partitioned InnoDB table was last updated by an INSERT, DELETE, or UPDATE. The UPDATE_TIME column of the INFORMATION_SCHEMA.PARTITIONS table now shows when a partition of a partitioned InnoDB table was last updated. (Bug #69990, Bug #17299181)

InnoDB: An assertion was raised on shutdown due to XA PREPARE transactions holding explicit locks. (Bug #20816223, Bug #76567)

InnoDB: Removal of a foreign key object from the data dictionary cache during error handling caused the server to exit. (Bug #20442523)

InnoDB: SHOW ENGINE INNODB STATUS output showed negative reservation and signal count values due to a counter overflow error. (Bug #20417397)

InnoDB: Estimates that were too low for the size of merge chunks in the result sorting algorithm caused a server exit. (Bug #20049521)

SHOW VARIABLES mutexes were being locked twice, resulting in a server exit. (Bug #20788853)

Under certain conditions, the libedit command-line library could write outside an array boundary and cause a client program crash. (Bug #20318154)

Host value matching for the grant tables could fail to use the most specific of values that contained wildcard characters. (Bug #20181776)

A user with a name of event_scheduler could view the Event Scheduler process list without the PROCESS privilege. (Bug #20007583, Bug #20754369)

SHOW GRANTS after connecting using a proxy user could display the password hash of the proxied user. (Bug #19817663)

For a prepared statement with an ORDER BY that refers by column number to a GROUP_CONCAT() expression that has an outer reference, repeated statement execution could cause a server exit. (Bug #19814337)

Loading corrupt spatial data into a MyISAM table could cause the server to exit during index building. (Bug #19573096)

A Provides rule in RPM .spec files misspelled “mysql-embedded” as “mysql-emdedded”. (Bug #76385, Bug #20734434)

Certain queries for the INFORMATION_SCHEMA TABLES and COLUMNS tables could lead to excessive memory use when there were large numbers of empty InnoDB tables. (Bug #72322, Bug #18592390)

MySQL failed to compile using OpenSSL 0.9.8e. (Bug #68999, Bug #16861371)

Functionality Added or Changed

Bugs Fixed

CMake support was updated to handle CMake version 3.1. (Bug #20344207)

The server now includes its version number when it writes the initial “starting” message to the error log, to make it easier to tell which server instance error log output applies to. This value is the same as that available from the version system variable. (Bug #74917, Bug #20052694)

Replication: When using a slave configured to use a special character set such as UTF-16, UTF-32, or UCS-2, the receiver (I/O) thread failed to connect. The fix ensures that in such a situation, if a slave's character set is not supported then default to using the latin1 character set. (Bug #19855907)

Ordering by a GROUP_CONCAT() result could cause a server exit. (Bug #19880368, Bug #20730220)

A malformed mysql.proc table row could result in a server exit for DROP DATABASE of the database associated with the proc row. (Bug #19875331)

Large values of the transaction_prealloc_size system variable could cause the server to allocate excessive amounts of memory. The maximum value has been adjusted down to 128K. A similar change was made for transaction_alloc_block_size. Transactions can still allocate more than 128K if necessary; this change reduces the amount that can be preallocated, as well as the maximum size of the incremental allocation blocks. (Bug #19770858, Bug #20730053)

A server exit could occur for queries that compared two rows using the <=> operator and the rows belonged to different character sets. (Bug #19699237, Bug #20730155)

Certain InnoDB errors caused stored function and trigger condition handlers to be ignored. (Bug #19683834, Bug #20094067)

The optimizer could raise an assertion due to incorrectly associating an incorrect field with a temporary table. (Bug #19612819, Bug #20730129)

The server could exit due to an optimizer failure to allocate enough memory for resolving outer references. (Bug #18782905, Bug #19892803)

Starting the server with start service or mysqld_safe could result in failure to use the correct plugin directory. (Bug #17619241)

Creating a FEDERATED table with an AUTO_INCREMENT column using a LIKE clause results in a server exit. (Bug #12671631)

Functionality Added or Changed

Bugs Fixed

SSL 2.0 and SSL 3.0 protocols are now explicitly disabled because they provide weak encryption. (Bug #19820550)

References: See also: Bug #19921150.

yaSSL was upgraded to version 2.3.7. (Bug #19695101, Bug #20201864)

The valid date range of the SSL certificates in mysql-test/std_data has been extended to the year 2029. (Bug #18366947)

InnoDB: An error occurred when the push_warning_printf function was invoked during server recovery. This function was previously used to print a warning message to the client. Also, current_thd was NULL when the server was restarted. (Bug #20144839)

InnoDB: A multiple-table delete operation caused the server to halt. (Bug #19815702)

Replication: If a DROP DATABASE statement failed on the master, mismatched tables could be left on the slave, breaking replication. This was caused by the DROP TABLE statement being binary logged if at least one table was deleted during the DROP DATABASE operation. The fix ensures that in such a situation the DROP TABLE statement is binary logged with the IF EXISTS option. (Bug #74890, Bug #20041860)

Unlocking a temporary table after locking and truncating it could cause a server exit. (Bug #19786309)

The Enterprise Encryption plugin could mishandle string arguments. (Bug #19688008, Bug #20730103)

FLUSH TABLES on a FEDERATED table failed if the table had been idle longer than the wait_timeout time plus the TCP keepalive time. (Bug #17599258)

Selecting all columns from INFORMATION_SCHEMA.TABLES did not reopen tables if they were in the table cache, but selecting a subset of those columns under the same conditions did reopen tables. (Bug #16869534)

MySQL failed to compile with GCC 4.9.1 in debug mode. (Bug #74710, Bug #19974500)

A file created for an internal temporary table could cause problems if the file was orphaned for some reason and the file name was reused for later queries. (Bug #32917, Bug #11747548)

Compilation Notes

Functionality Added or Changed

Bugs Fixed

CMake workarounds for older OS X and XCode versions were removed. On OS X, compilation always uses Clang, even for 32-bit builds.

Compilation on OS X is now supported for OS X 10.8 and up, using XCode 5 and up. Compilation on older versions may work but is unsupported. (Bug #18510941)

Previously, the MYSQL_MAINTAINER_MODE CMake option was turned on by default for debug builds and off for release builds, and MYSQL_MAINTAINER_MODE caused -Werror to be enabled when building with GCC. This made it cumbersome to enable -Werror under certain conditions, such as when compiling with Clang.

Now, MYSQL_MAINTAINER_MODE is on by default when compiling debug builds with GCC, and MYSQL_MAINTAINER_MODE enbles -Werror regardless of whether GCC or Clang is used. Enabling -Werror with Clang can be done simply by explicitly setting -DMYSQL_MAINTAINER_MODE=1 when running CMake. In addition, some compilation warnings reported by Clang 3.4 were fixed, making it possible to build the default debug build with -Werror. (Bug #18313717)

Build support was modified to produce the same warnings for Clang as for gcc. (Bug #17959689)

CMake configuration for the Clang compiler sets more appropriate flags for building on Linux. Specifically, -g -fno-omit-frame-pointer -fno-strict-aliasing is now added. (Bug #17633291)

yaSSL was upgraded to version 2.3.5. (Bug #19695101, Bug #20201864)

InnoDB: An ALTER TABLE operation raised an assertion. When a foreign key object was removed from the dictionary cache, an incorrect foreign key object was removed from the rb-tree. (Bug #19908343)

References: This issue is a regression of: Bug #18806829.

InnoDB: In debug builds, setting the innodb_limit_optimistic_insert_debug debug configuration option to 1 caused an infinite B-tree page split. (Bug #19904003, Bug #74605)

InnoDB: The dict_set_corrupted() function attempted to update the clustered index of the SYS_INDEXES data dictionary table incorrectly. (Bug #19584379)

InnoDB: A procedure, called from a function to perform an operation on a temporary table, caused the server to halt. (Bug #19306524)

InnoDB: A CREATE TABLE operation that failed when innodb_strict_mode was enabled succeeded without printing a warning when innodb_strict_mode was disabled. (Bug #17852083)

Replication: When using a MySQL version that had been compiled with the WITH_DEBUG option enabled, using expire_logs_days to purge binary logs caused a restart to crash the server. This problem arose after the fix for Bug #17283409. The fix ensures that current_thd is checked before calling DEBUG_SYNC(). (Bug #19553099)

Replication: A corrupted header length in FORMAT_DESCRIPTION_LOG_EVENT could cause the server to stop unexpectedly. This was due to FORMAT_DESCRIPTION_LOG_EVENT being considered invalid if the header length was too short. (Bug #19145712)

Replication: Start log events were not checked by slaves for minimum size. (Bug #19145698)

Replication: A kernel mutex contention was being caused because mysqlbinlog was calling localtime() for every event read, which in turn called stat(/etc/localtime). This fix ensures that mysqlbinlog uses localtime_r(), which is optimized to store the read only timezone internal structure. This also means that mysqlbinlog now establishes the time zone at the beginning of processing and you can not change it during processing. This is the same behavior as MySQL server. (Bug #72701, Bug #18808072)

Replication: The global scope for the sql_log_bin system variable has been deprecated, and this variable can now be set with session scope only. The statement SET GLOBAL SQL_LOG_BIN now produces an error. It remains possible for now to read the global value of sql_log_bin, but you should act to remove from your applications any dependencies on reading this value, as the ability to do so will be removed in a future MySQL release. (Bug #67433, Bug #15868071)

Previously, InnoDB permitted a foreign key to be created which referenced a parent table for which the user did not have sufficient privileges. Now, the user must have at least one of the SELECT, INSERT, UPDATE, DELETE, or REFERENCES privileges for the parent table to create a foreign key. (Bug #18790730)

On Windows, the replace utility did not work. (Bug #16581605)

Binary MySQL distributions for OS X 10.8 and up now bundle the MySQL.prefPane and MySQLStartupItem.pkg tools into the main package as configurable options instead of separate packages. (Bug #74123, Bug #19701502)

On CentOS 6, specifying a relative path name for the --socket option caused MySQL startup script failure. (Bug #74111, Bug #19775856)

The IS_FREE_LOCK() and IS_USED_LOCK() function implementations contained a race condition due to which they could access freed memory when a user lock was concurrently checked and freed. Accessing freed memory could result in an incorrect function return value or server exit. (Bug #73123, Bug #19070633)

mysql_setpermission failed to properly quote user names in SQL statements that it generated. (Bug #66317, Bug #14486004)

InnoDB: An ALTER TABLE ... ADD FOREIGN KEY operation could cause a serious error. (Bug #19471516, Bug #73650)

InnoDB: With a transaction isolation level less than or equal to READ COMMITTED, gap locks were not taken when scanning a unique secondary index to check for duplicates. As a result, duplicate check logic failed allowing duplicate key values in the unique secondary index. (Bug #19140907)

References: This issue is a regression of: Bug #16133801.

InnoDB: During recovery, a segmentation fault would occur when marking a table as corrupt. (Bug #18942294)

References: This issue is a regression of: Bug #11830883.

yaSSL client code did not validate the encryption size or session ID length, which could cause the client to exit. (Bug #19463277, Bug #19463565)

MySQL installation from RPM packages could fail if Postfix had been installed using yum. (Bug #19392127)

yaSSL could fail preauthorization if the client supplied inaccurate buffer lengths. (Bug #19370676, Bug #19355577)

Competition between threads could lead to timeout failure trying to rotate the audit log file. (Bug #19184973)

On Linux (OEL6), if Sun DTrace was installed, the MySQL build failed. (Bug #19149091)

LPAD() and RPAD() could cause a server exit if the pad string argument was not well formed. (Bug #18935421)

The optimizer could create a zero-length column for a temporary table, causing a server exit. (Bug #18928848)

MOD for very small decimal right-hand arguments could cause a server exit. (Bug #18469276)

The client library now includes a call to X509_verify_cert_error_string() in the SSL certificate verification code, to be more robust in detecting invalid certificates. (Bug #18384260)

The thread_concurrency system variable is deprecated, but no warning resulted from setting it at server startup. (Bug #17873011)

Sending a SIGQUIT or SIGINT signal to mysql could result in a glibc double free or corruption error. (Bug #17297324)

On EL7, installation of MySQL from RPM packages could fail if postfix had previously been installed using yum. (Bug #73507, Bug #19392051, Bug #19392149)

mysql_upgrade could fail if the mysql.user table contained multiple accounts with the same user name and host name where the host name differed in lettercase. This is still not permitted, but now mysql_upgrade prints a more informative error message to indicate the nature of the problem:

ERROR 1644 (45000): Multiple accounts exist for user_name, host_name
that differ only in Host lettercase; remove all except one of them

(Bug #72066, Bug #18415196)

If the general query log or slow query log file was set to a FIFO or socket file, and the file reader went away, the server stopped executing statements. Now the server detects such files, logs an error message, and continues with the appropriate log disabled. (Bug #67088, Bug #14757009)

LIKE matches failed for code points of HALF WIDTH KATAKANA in the sjis and cp932 character sets. (Bug #47641, Bug #11755818)

Functionality Added or Changed

Bugs Fixed

CMake support was updated to handle CMake version 3. (Bug #19001781)

The timed_mutexes system variable has no effect and is deprecated. (Bug #18277305)

InnoDB: Opening a parent table that has thousands of child tables could result in a long semaphore wait condition. (Bug #18806829)

Partitioning: Selecting from a table having multiple columns in its primary key and partitioned by LIST COLUMNS(R), where R was the last (rightmost) column listed in the primary key definition, returned an incorrect result. (Bug #17909699, Bug #71095)

Replication: When using row-based replication, updating or deleting a row on the master that did not exist on the slave led to failure of the slave when it tried to process the change. This problem occurred with InnoDB tables lacking a primary key. (Bug #18432495, Bug #72085)

Replication: Quotation marks were not always handled correctly by LOAD DATA INFILE when written into the binary log. (Bug #18207212, Bug #71603)

Replication: A group of threads involved in acquiring locks could deadlock when the following events occurred:

This leads to the 4 threads deadlocking in the same order which the threads have been listed here.

This problem arises because there are ordering rules for LOCK_log and LOCK_index, as well as rules for ordering LOCK_thread_count and LOCK_thd_data, but there are no rules for ordering across these two sets of locks. This was because the internal mysqld_list_processes() function invoked by SHOW PROCESSLIST acquired LOCK_thread_count for the complete lifetime of the function as well as acquiring and releasing each thread's LOCK_thd_data. Now this function takes a copy of the threads from the global thread list and performs its traversal on these, and only after releasing LOCK_thread_count. During this traversal, removal from the global thread list is blocked using LOCK_thd_remove such that the copies that would otherwise be destroyed by the removal remain valid during traversal. The locking order following this fix is shown here:

LOCK_thd_remove -> LOCK_thd_data -> LOCK_log -> LOCK_index -> LOCK_thread_count

(Bug #69954, Bug #17283409)

References: See also: Bug #73475, Bug #19364731, Bug #19365180.

SHA and MD5 functions failed for operations using the internal filename character set and could cause a server exit. (Bug #18786138)

Large arguments passed to mysqldump could lead to buffer overflow and program exit. (Bug #18779944)

ALTER TABLE on a partitioned table could result in the wrong storage engine being written into the table's .frm file and displayed in SHOW CREATE TABLE. (Bug #18618561)

Compiler flags were not passed to DTrace, causing problems for 32-bit builds cross-compiled on 64-bit platforms. (Bug #18593044)

With the max_heap_table_size system variable set to a large value (20GB), creation of a temporary table or a table using the MEMORY storage engine caused a server exit. (Bug #18463911)

If MySQL was built with the -DINSTALL_LIBDIR=lib64 option, mysql_config did not work if the MySQL package was unpacked into a location with a different installation prefix. Also, mysql_config did not work for some RPM builds because it used an incorrect installation prefix. (Bug #18382225)

yaSSL code had an off-by-one error in certificate decoding that could cause buffer overflow.

yaSSL code had an opendir() without a corresponding closedir(). (Bug #18178997, Bug #17201924)

mysqladmin password masked the old password given on the command line, but not the new password. (Bug #18163964)

MyISAM temporary files could be used to mount a code-execution attack. (Bug #18045646)

If a query had both MIN()/MAX() and aggregate_function(DISTINCT) (for example, SUM(DISTINCT)) and was executed using Loose Index Scan, the result values of MIN()/MAX() were set improperly. (Bug #17217128)

For UNION statements, the rows-examined value was calculated incorrectly. This was manifest as too-large values for the ROWS_EXAMINED column of Performance Schema statement tables (such as events_statements_current). (Bug #17059925)

Clients could determine based on connection error message content whether an account existed. (Bug #16513435, Bug #17357528, Bug #19273967)

An assertion could be raised when creating a index on a prefix of a TINYBLOB or GEOMETRY column in an InnoDB column. (Bug #16368875, Bug #18776592, Bug #17665767)

Use of a nonmultibyte algorithm for skipping leading spaces in multibyte strings could cause a server exit. (Bug #12368495, Bug #18315770)

MySQL did not compile with Bison 3. (Bug #71250, Bug #18017820, Bug #18978946)

Deadlock could occur if three threads simultaneously performed INSTALL PLUGIN, SHOW VARIABLES, and mysql_change_user(). (Bug #71236, Bug #18008907, Bug #72870, Bug #18903155)

If there was a predicate on a column referenced by MIN() or MAX() and that predicate was not present in all the disjunctions on key parts earlier in the compound index, Loose Index Scan returned an incorrect result. (Bug #71097, Bug #17909656)

Uninstalling and reinstalling semisynchronous replication plugins while semisynchronous replication was active caused replication failures. The plugins now check whether they can be uninstalled and produce an error if semisynchronous replication is active. To uninstall the master-side plugin, there must be no semisynchronous slaves. To uninstall the slave-side plugin, there must be no semisynchronous I/O threads running. (Bug #70391, Bug #17638477)

File permissions and line endings of several test and configuration files were made more consistent to avoid warnings from package checkers. (Bug #68521, Bug #16415173, Bug #16395459, Bug #68517, Bug #16415032, Bug #71112, Bug #17919313, Bug #71113, Bug #17919422)

For a view defined on a UNION, the server could create an invalid view definition. (Bug #65388, Bug #14117018, Bug #72018, Bug #18405221)

InnoDB: For each insert, memset would be called three times to allocate memory for system fields. To reduce CPU usage, the three memset calls are now combined into a single call. (Bug #17858679, Bug #71014)

Replication: When used on a table employing a transactional storage engine, a failed TRUNCATE TABLE was still written to the binary log and thus replayed on the slave. This could lead to inconsistency when the master retained data that was removed on the slave.

Now in such cases TRUNCATE TABLE is logged only when it executes successfully. (Bug #17942050, Bug #71070)

For indexes on prefixes or character string columns, index corruption could occur for assignment of binary data to the column due to improper character counting. (Bug #18359924)

Certain INFORMATION_SCHEMA queries could cause a server exit. (Bug #18319790)

Solaris-specific scripts were included in and installed by non-Solaris packages. (Bug #18305641)

EXPLAIN on a query with an EXISTS subquery containing a UNION could cause a server exit. Multiple executions of a prepared EXPLAIN on a UNION of subqueries could cause a server exit. (Bug #18167356)

The client library could cause clients to exit due to incorrectly mapping the client error number to the corresponding message, if reallocation of packet buffer memory occurred. (Bug #18080920)

Executing a correlated subquery on an ARCHIVE table which has an AUTO_INCREMENT column caused the server to hang. (Bug #18065452)

Calling mysql_get_server_version() with an invalid connection handler argument caused the client to exit. Now it returns 0 and reports a CR_COMMANDS_OUT_OF_SYNC error. (Bug #18053212)

On Windows, calling mysql_thread_init() call without mysql_init() caused the client to exit. windows. Now it returns a nonzero result because it is an error to call mysql_thread_init() before the client library is initialized with mysql_library_init(). (Bug #17514920)

A statement of the following form broke row-based replication because it created a table having a field of data type BIGINT with a display width of 3000, which is beyond the maximum acceptable value of 255:

CREATE TABLE t1 AS SELECT REPEAT('A',1000) DIV 1 AS a;

(Bug #71179, Bug #17994219)

CMake produced not-useful warnings about INTERFACE_LINK_LIBRARIES policy. (Bug #71089, Bug #17905155, Bug #17894997)

LOAD DATA LOCAL INFILE could use all CPU if import errors occurred when there were no line delimiters. (Bug #51840, Bug #11759519)

Functionality Added or Changed

Bugs Fixed

On Solaris, mysql_config --libs now includes -R/path/to/library so that libraries can be found at runtime. (Bug #18235669)

InnoDB: A regression introduced by Bug #14329288 would result in a performance degradation when a compressed table does not fit into memory. (Bug #18124788, Bug #71436)

References: This issue is a regression of: Bug #14329288.

InnoDB: The maximum value for innodb_thread_sleep_delay is now 1000000 microseconds. The previous maximum value (4294967295 microseconds on 32-bit and 18446744073709551615 microseconds on 64-bit) was unnecessarily large. Because the maximum value of innodb_thread_sleep_delay is limited by the value set for innodb_adaptive_max_sleep_delay (when set to a non-zero value), the maximum value for innodb_thread_sleep_delay is now the same as the maximum value for innodb_adaptive_max_sleep_delay. (Bug #18117322)

InnoDB: In debug builds, creating a unique index on a binary column, with input data containing duplicate keys, would cause an assertion. (Bug #18010711)

InnoDB: InnoDB failed to start when innodb_data_file_path specified the data file size in kilobytes by appending K to the size value. (Bug #16287752)

InnoDB: An insert buffer merge would cause an assertion error due to incorrectly handled ownership information for externally stored BLOBs.

InnoDB: Assertion failure in thread thread_num in file ibuf0ibuf.cc line 4080
InnoDB: Failing assertion: rec_get_deleted_flag(rec, page_is_comp(page))

(Bug #14668683)

InnoDB: Decreasing the auto_increment_increment value would have no affect on the next auto-increment value. (Bug #14049391, Bug #65225)

Replication: The server did not handle correctly the insertion of a row larger than 4 GB when using row-based replication. (Bug #17081415)

Replication: When using row-based replication, an additional auto-increment column on the slave version of a table was not updated correctly; a zero was inserted instead. (Bug #17066269, Bug #69680)

Replication: Statements involving the Performance Schema tables should not be written to the binary log, because the content of these tables is applicable only to a given MySQL Server instance, and may differ greatly between different servers in a replication topology. The database administrator should be able to configure (INSERT, UPDATE, or DELETE) or flush (TRUNCATE TABLE) performance schema tables on a single server without affecting others. However, when replicating from a MySQL 5.5 master to a MySQL 5.5 or later slave, warnings about unsafe statements updating Performance Schema tables were elevated to errors. For MySQL 5.6 and later slaves, this prevented the simultaneous use of performance_schema and GTIDs (see Replication with Global Transaction Identifiers, in the MySQL 5.6 Manual).

This fix causes all updates on tables in the performance_schema database to be filtered on the master and not replicated, regardless of the type of logging that is in effect. Prior to this fix, statements using were handled by being marked as unsafe for replication, which caused warnings during execution; the statements were nonetheless written to the binary log, regardless of the logging format in effect.

Existing replication behavior for tables in the INFORMATION_SCHEMA database is not changed by this fix.

For more information, see MySQL Performance Schema. (Bug #16814264)

References: See also: Bug #14741537, Bug #18259193.

While printing the server version, the mysql client did not check for buffer overflow in a string variable. (Bug #18186103)

Compilation failed if MySQL was configured with CFLAGS set to include a -Werror option with an argument. (Bug #18173037)

A shared libmysqld embedded server library was not built on Linux. A new WITH_EMBEDDED_SHARED_LIBRARY CMake option now makes this possible. (Bug #18123048, Bug #16430656, Bug #68559)

Contraction information in a collation could be mishandled, resulting in incorrect decisions about whether a character is part of a contraction, and miscalculation of contraction weights. (Bug #17760379)

DROP TRIGGER succeeded even with the read_only system variable enabled. (Bug #17503460)

Updating the setup_instruments Performance Schema table on a replication master caused a slave to exit. (Bug #14539290)

When run by root, mysqld --help --verbose exited with a nonzero error code after displaying the help message. (Bug #70058, Bug #17324415)

A deadlock error occurring during subquery execution could cause an assertion to be raised. (Bug #69969, Bug #17307201)

For system variables that take a string value, SET statements permitted an unquoted value, but values that contained dots were parsed incorrectly and only part of the value was assigned. For example, SET GLOBAL slow_query_log_file = my_slow.log assigned the value my_slow. Now such values must be quoted or an error occurs. (Bug #69703, Bug #17075846)

MySQL client programs from a Community Edition distribution could not connect using SSL to a MySQL server from an Enterprise Edition. This was due to a difference in certificate handling by yaSSL and OpenSSL (used for Community and Enterprise, respectively). OpenSSL expected a blank certificate to be sent when not all of the --ssl-ca, --ssl-cert, and --ssl-key options were specified, and yaSSL did not do so. To resolve this, yaSSL has been modified to send a blank certificate when an option is missing. (Bug #68788, Bug #16715064)

Due to a race condition, it was possible for two threads to end up with the same query ID for different queries. (Bug #58785, Bug #11765785)

On Windows, mysql_install_db.pl could be run only from within the bin directory under the installation directory. (Bug #42421, Bug #11751526)

Functionality Added or Changed

Bugs Fixed

CMake now supports a -DTMPDIR=dir_name option to specify the default tmpdir value. If unspecified, the value defaults to P_tmpdir in <stdio.h>. Thanks to Honza Horak for the patch. (Bug #68338, Bug #16316074)

InnoDB: Table renaming errors would appear in the LATEST FOREIGN KEY ERROR section of the SHOW ENGINE INNODB STATUS output. (Bug #12762390, Bug #61746)

Partitioning: Queries using the index_merge optimization (see Index Merge Optimization) could return invalid results when run against tables that were partitioned by HASH. (Bug #17588348, Bug #70588)

References: See also: Bug #16862316, Bug #17648468, Bug #18167648.

Partitioning: When no partition had returned a row since the last HA_ERR_KEY_NOT_FOUND error, the use of uninitialized memory in the priority queue used for returning rows in sorted order could lead to a crash of the server. (Bug #17401628)

Replication: When log_warnings is greater than 1, the master prints binary log dump thread information—containing the slave server ID, binary log file name, and binary log position—in mysqld.1.err. A slave server ID greater than 2 billion was printed with a negative value in such cases. (Bug #17641586, Bug #70685)

Replication: mysqlbinlog --verbose failed when it encountered a corrupt row event in the binary log. Such a row event could also cause the slave to fail. (Bug #17632978)

References: See also: Bug #16960133.

Replication: Invalid event offsets in the binary log were not always handled correctly, which could lead to replication failure. (Bug #16736412, Bug #69087)

The cache used for the Index Merge access method was freed only after successful retrieval of all rows. Interruption or failure of the operation led to a file descriptor leak. (Bug #17708621)

For utf8 and utf8mb4 strings, handler functions unnecessarily called a Unicode conversion function. (Bug #14057034)

Use of a nonmultibyte algorithm for skipping leading spaces in multibyte strings could cause a server exit. (Bug #12368495, Bug #18315770)

The prototype of the Performance Schema instrumentation API mysql_cond_timedwait() call was fixed to be drop-in compatible with pthread_cond_timedwait(). This fix affects only implementers of third-party plugins. (Bug #70628, Bug #17702677)

For the path specified with the --basedir option, mysql_plugin attempted to unlink the path rather than free the memory in which the path was stored. (Bug #69752, Bug #17168602)

On Windows, the --local-service server option did not work, and was not displayed in the --help message. (Bug #69637, Bug #17049656)

For the utf8_bin collation, ORDER BY LOWER(col_name) could produce incorrect ordering. (Bug #69005, Bug #16691598)

COUNT(DISTINCT) sometimes produced an incorrect result when the last read row contained a NULL value. (Bug #68749, Bug #16539979, Bug #71028, Bug #17867117)

Some scripts displayed out-of-date information regarding where to report bugs. (Bug #68742, Bug #16530527)

Updating a FEDERATED table with UPDATE... JOIN caused a server exit when the local table contained a single row and that row could be joined to a row in the FEDERATED table. (Bug #68354, Bug #16324629)

mysql_install_db referred to the obsolete mysqlbug script for reporting problems. It now refers to http://bugs.mysql.com/ instead. (Bug #29716, Bug #11746921)

Packaging Notes

Functionality Added or Changed

Bugs Fixed

Previously, MySQL Server distributions included the MySQL Reference Manual in Info format (the Docs/mysql.info file). Because the license for the manual restricts redistribution, its inclusion in Community packages caused problems for downstream redistributors, such as those who create Linux distributions. Community distributions of MySQL Server no longer include the mysql.info file, to make the repackaging and redistribution process easier (for example, the source tarball and its checksum can be used directly). This change applies to all source and binary Community packaging formats. Commercial (Enterprise) distributions are unchanged.

For those who wish to continue using the MySQL Reference Manual in Info format, we have made it available at http://dev.mysql.com/doc/.

A new CMake option, WITH_ASAN, permits enabling AddressSanitizer for compilers that support it. (Bug #17435338)

Attempts to use the thread_concurrency system variable (which has an effect only for Solaris 8 and earlier) now indicate that it has no effect when that is the case. (Bug #67944, Bug #16032946)

InnoDB: CHECK TABLE would ignore the QUICK option. (Bug #17513737)

InnoDB: Running SHOW ENGINE INNODB STATUS on one connection thread and killing that thread by running a KILL CONNECTION statement from a different connection thread would result in a severe error. (Bug #17474166)

InnoDB: In debug builds, test case failures would occur due to ibuf_contract_ext performing merges and dict_stats_update returning evicted pages back into the buffer pool while ibuf_change_buffering_debug is enabled. (Bug #17446090)

InnoDB: InnoDB failed to return an error when attempting to run a query after discarding the tablespace. (Bug #17431533)

InnoDB: When the change buffer is enabled, InnoDB failed to write a transaction log record when merging a record from the insert buffer to a secondary index page if the insert was performed as an “update-in-place”. (Bug #16752251, Bug #69122)

InnoDB: When index_read_map is called for an exact search and fails to return a record due to non-matching search criteria, the cursor would be positioned on the next record after the searched key. A subsequent call to index_next would return the next record instead of returning the previous non-matching row, thereby skipping a record. (Bug #14621190, Bug #15965874, Bug #17314241, Bug #70038, Bug #17413093, Bug #12860669, Bug #60220, Bug #17565888)

InnoDB: Converting a table with a large number of columns from MyISAM to InnoDB would cause an assertion due to insufficient log buffer space. Instead of asserting, InnoDB now attempts to increase log buffer size automatically if the redo log size is too large. (Bug #11758196, Bug #50366)

Partitioning: The storage engine was set incorrectly during a rebuild of a partition; the table storage engine was ignored and the default storage engine used instead. Thus, in MySQL 5.1, it was possible for REBUILD PARTITION to change the partition storage engine from InnoDB to MyISAM, and for the reverse (rebuilding partitions of MyISAM tables causing the partitions to use InnoDB) to occurin MySQL 5.5 and later. Now, when rebuilding partitions, the storage engine actually used by the table is checked and used by the handler for the rebuild operation, so that the partition storage engine is not inadvertently changed. (Bug #17559867)

Partitioning: After disabling the parent table's indexes with ALTER TABLE ... DISABLE KEYS, rebuilding any of its partitions enabled the indexes on those partitions, leading MyISAM to fail with an error when the optimizer tried to use one of the affected indexes.

Now in such cases, we check for disabled indexes on the table before rebuilding any of its partitions. If the indexes have been disabled, then we disable them on the partition following the rebuild. (Bug #16051817)

Replication: A replication master did not handle correctly the disabling of the semisync plugin on the master and the slave, with a subsequent stopping of the slave. (Bug #17460821, Bug #70349)

Replication: The final argument in the SET clause of a LOAD DATA ... SET statement was repeated in the binary log. (Bug #17429677, Bug #70277)

Replication: When an error encountered by the dump thread while reading events from the active binary log file was a temporary error, so that the dump thread tried to read the event, it was possible for the dump thread to seek the wrong position, which could cause one or more events to be resent. To prevent this, the thread's position is obtained after each correct read of an event.

In addition, with this fix, only binary logs that are not closed normally are marked as possibly being corrupted.

Finally, two warnings are added; these are now returned when a dump thread encounters a temporary error. (Bug #17402313)

Replication: Setting rpl_semi_sync_master_enabled while the master was waiting for a reply from the slave could in some cases cause the master to fail. (Bug #17327454, Bug #70045)

Replication: The value of LAST_INSERT_ID() was not correctly replicated when filtering rules were used on the slave. (Bug #17234370, Bug #69861)

Enabling Index Merge optimizer switches and setting a small sort_buffer_size value could lead to a server exit. (Bug #17617945)

Some license and documentation files were missing from Windows MSI packages. (Bug #17584523)

The filesort implementation sometimes failed to allocate enough buffer space, leading to a server exit. (Bug #17326567)

The mysql_options() C API function could leak memory if called more than once with the MYSQL_SET_CLIENT_IP option. (Bug #17297012)

The CONV() function could call abs(INT_MIN), which is undefined, and cause a server exit. (Bug #17296644)

An error array in the SSL code was missing a comma, leading to implicit concatenation of adjacent messages and a resulting off-by-one error in the relationship between error numbers and messages. (Bug #17294150)

GROUP_CONCAT() with an invalid separator could cause a server exit. (Bug #16870783)

An internal InnoDB string routine could write past the end of a buffer. (Bug #16765410)

Using the binary client/server protocol, the second execution of a prepared statement for a query with parameters in the LIMIT clause raised an assertion. (Bug #16346241)

The usual failed-login attempt accounting was not applied to failed COM_CHANGE_USER commands. (Bug #16241992, Bug #17357535)

Very long database names in queries could cause the server to exit. (Bug #15912213, Bug #16900358)

Standalone Windows MSI packages did not have the ALLUSERS property set. They now set ALLUSERS=1. For earlier MSI packages in this MySQL series, a workaround is to use the following command:

C:\> msiexec /i msi_installer_name ALLUSERS=1

(Bug #14647206)

Some .pdb files were missing from Windows Zip archive distributions. (Bug #13878021)

COUNT(DISTINCT) should not count NULL values, but they were counted when the optimizer used Loose Index Scan. (Bug #69841, Bug #17222452)

For queries of the form UPDATE ... WHERE unique_key ORDER BY ... LIMIT ..., incorrect rows could be updated. Unique keys permit multiple NULL values, but the optimizer did not always consider all of them. (Bug #68656, Bug #16482467)

The my_b_vprintf() function could produce incorrect results for long integers on 64-bit systems. (Bug #67386, Bug #16978278)

Host names in grant tables are stored in lowercase, but mysql_install_db could fail to observe this convention, leading to accounts that could not be dropped with DROP USER. (Bug #62255, Bug #12917164, Bug #62254, Bug #12917151)

Killing a query that is performing a filesort operation resulted in an ER_SERVER_SHUTDOWN (Server shutdown in progess) error. (Bug #18256, Bug #11745656)

Audit Log Notes

Bugs Fixed

MySQL 5.7 changed audit log file output to a new format that has better compatibility with Oracle Audit Vault. This format has been backported to MySQL 5.5 and it is possible to select either the old or new format using the new audit_log_format system variable, which has permitted values of OLD and NEW (default OLD). For details about each format, see The Audit Log File.

In addition, when the audit log plugin rotates the audit log file, it uses a different file name format. For a log file named audit.log, the plugin previously renamed the file to audit.log.TIMESTAMP. The plugin now renames the file to audit.log.TIMESTAMP.xml to indicate that it is an XML file.

If you change the value of audit_log_format, use this procedure to avoid writing log entries in one format to an existing log file that contains entries in a different format:

The API for writing audit plugins has also changed. The mysql_event_general structure has new members to represent client host name and IP address, command class, and external user. For more information, see Writing Audit Plugins.

InnoDB; Partitioning: Following any query on the INFORMATION_SCHEMA.PARTITIONS table, InnoDB index statistics as shown in the output of statements such as SELECT * FROM INFORMATION_SCHEMA.STATISTICS were read from the last partition, instead of from the partition containing the greatest number of rows. (Bug #11766851, Bug #60071)

References: See also: Bug #16882435, Bug #69179.

InnoDB: The row_sel_sec_rec_is_for_clust_rec function would incorrectly prepare to compare a NULL column prefix in a secondary index with a non-NULL column in a clustered index. (Bug #17312846)

InnoDB: An incorrect purge would occur when rolling back an update to a delete-marked record. (Bug #17302896)

InnoDB: InnoDB would rename a user-defined foreign key constraint containing the string “_ibfk_” in its name, resulting in a duplicate constraint. (Bug #17076737, Bug #69693, Bug #17076718, Bug #69707)

InnoDB: Rolling back an INSERT after a failed BLOB write would result in an assertion failure. The assertion has been modified to allow NULL BLOB pointers if an error occurs during a BLOB write. (Bug #16971045)

InnoDB: A regression introduced with the fix for Bug #11762038 would cause InnoDB to raise an incorrect error message. The message stated that, “InnoDB cannot delete/update rows with cascading foreign key constraints that exceed max depth of 20”. The error message would occur when killing connections reading from InnoDB tables that did not have foreign key constraints. (Bug #16710923)

References: This issue is a regression of: Bug #11762038.

InnoDB: The documentation incorrectly stated that START TRANSACTION WITH CONSISTENT SNAPSHOT provides a consistent snapshot only if the current isolation level is REPEATABLE READ or SERIALIZABLE. START TRANSACTION WITH CONSISTENT SNAPSHOT only works with REPEATABLE READ. All other isolation levels are ignored. The documentation has been revised and a warning is now generated whenever the WITH CONSISTENT SNAPSHOT clause is ignored. (Bug #14017206, Bug #65146)

InnoDB: The srv_master_thread background thread, which monitors server activity and performs activities such as page flushing when the server is inactive or in a shutdown state, runs on a one second delay loop. srv_master_thread failed to check if the server is in a shutdown state before sleeping. (Bug #13417564, Bug #63276)

InnoDB: An infinite loop could occur in buf_page_get_gen when handling compressed-only pages. (Bug #12560151, Bug #61132)

Partitioning: Creating a table t1 using CREATE TABLE ... PARTITION BY LIST ... PARTITION ... VALUES IN (NULL), then attempting to execute CREATE TABLE ... LIKE t1 caused the server to fail. (Bug #16860588)

Replication: A slave using row-based replication was unable to read the rows containing columns of type MYSQL_TYPE_DECIMAL properly (old-style decimal, used prior to MySQL 5.0.3). Now the slave throws an error if it receives this type of data. You can convert the old-style DECIMAL format to the binary format used in current MySQL releases with ALTER TABLE; see Upgrading from MySQL 4.1 to 5.0, for more information. (Bug #16416302)

Replication: DROP TEMP TABLE IF EXISTS statements could lead to failures in applying the binary log during point-in-time recovery operations. This is due to the fact that, when using row-based replication, the server appends IF EXISTS to any DROP TEMPORARY TABLE statements written to the binary log, and that the slave SQL thread does not check * wildcard filter rules for DROP TEMPORARY TABLE IF EXISTS. If --log-slave-updates was also enabled on the slave, such a statement was preceded by a USE statement. If the database referred by the USE statement did not exist, the statement failed, and stopped replication.

Now, when writing DROP TEMPORARY TABLE IF EXISTS into the binary log, no USE statement is written, and the table name in the DROP TEMPORARY TABLE statement is a fully qualified table name. (Bug #16290902)

Savepoints could not be used successfully following an ER_LOCK_DEADLOCK error (or ER_LOCK_WAIT_TIMEOUT error, if innodb_rollback_on_timeout was enabled). (Bug #17356954)

References: This issue is a regression of: Bug #14188793.

Within a stored program, comparison of the value of a scalar subquery with an IN clause resulted in an error for the first execution and raised an assertion for the second execution. (Bug #17029399)

The my_strtoll10() function could incorrectly convert some long string-format numbers to numeric values and fail to set the overflow flag. (Bug #16997513)

A race condition in the thread pool plugin could cause status variables such as Aborted_connects not to be incremented and permitting concurrent kills to happen for the same thread ID. (Bug #16959022)

Within a stored procedure, repeated execution of a prepared CREATE TABLE statement for a table with partitions could cause a server exit. (Bug #16614004)

Deadlocks involving metadata locks and InnoDB deadlocks were both reported as an ER_LOCK_DEADLOCK error, but only InnoDB deadlocks rolled back the transaction. Now both deadlocks roll back the transaction. (Bug #14188793)

For queries that accessed an INFORMATION_SCHEMA table in a subquery, an attempt to lock a mutex that had already been locked could cause a server crash. (Bug #11765744)

RPM packages did not provide lowercase tags for their contents. For example, a server RPM indicated that it provided MySQL-server, but not mysql-server. (Bug #69830, Bug #17211588)

InnoDB deadlock caused transaction rollback but did not release metadata locks, blocking concurrent DDL on the transaction tables until the connection that got the deadlock issued an explicit COMMIT or ROLLBACK. (Bug #69668, Bug #17054007)

mysqldump wrote SET statements as SET OPTION, which failed when reloaded because the deprecated OPTION keyword has been removed from SET syntax. (Bug #67507, Bug #15844882)

For failure to create a new thread for the event scheduler, event execution, or new connection, no message was written to the error log. This could lead to the impression that the event scheduler was running normally when it was not. (Bug #67191, Bug #14749800, Bug #16865959)

If one connection changed its default database and simultaneously another connection executed SHOW PROCESSLIST, the second connection could access invalid memory when attempting to display the first connection's default database. memory. (Bug #58198, Bug #11765252)

Functionality Added or Changed

Bugs Fixed

Previously, program options could be specified in full or as any unambiguous prefix. For example, the --compress option could be given to mysqldump as --compr, but not as --comp because the latter is ambiguous. Option prefixes now are deprecated. They can cause problems when new options are implemented for programs. A prefix that is currently unambiguous might become ambiguous in the future. If an unambiguous prefix is given, a warning now occurs to provide feedback. For example:

Warning: Using unique option prefix compr instead of compress is
deprecated and will be removed in a future release. Please use the
full name instead.

Option prefixes are no longer supported in MySQL 5.7; only full options are accepted. (Bug #16996656)

comp_err now checks to make sure that new errors are not being added to MySQL 5.1 or 5.5 because the set of errors for these series is frozen. (Bug #16807394)

Performance; Important Change; InnoDB: InnoDB failed to open a tablespace that has multiple data files. This removes the known limitation that was in MySQL Server 5.6.12. (Bug #17033706, Bug #69623)

Performance; InnoDB: When innodb_thread_concurrency is set to a non-zero value, there was a possibility that all innodb_concurrency_tickets would be released after each row was read, resulting in a concurrency check after each read. This could impact performance of all queries. One symptom could be higher system CPU usage. We strongly recommend that you upgrade to MySQL Server 5.6.13 if you use this setting. This could cause a performance drop between MySQL Server 5.5.x and 5.6.x. (Bug #68869, Bug #16622478)

InnoDB: When CHECK TABLE found a secondary index that contained the wrong number of entries, it would report an error but not mark the index as corrupt. CHECK TABLE now marks the index as corrupt when this error is encountered, but only the index is marked as corrupt, not the table. As a result, only the index becomes unusable until it is dropped and rebuilt. The table is unaffected. (Bug #16914007)

InnoDB: InnoDB would attempt to gather statistics on partially created indexes. (Bug #16907783)

InnoDB: The two INFORMATION_SCHEMA tables for the InnoDB buffer pool could show an invalid page type for read-fixed blocks. This fix will show the unknown page type for blocks that are I/O-fixed for reading. (Bug #16859867)

InnoDB: During an insert buffer merge, InnoDB would invoke lock_rec_restore_from_page_infimum() on a potentially invalid record pointer. (Bug #16806366)

InnoDB: Valgrind testing returned memory leak errors which resulted from a regression introduced by the fix for Bug #11753153. The dict_create_add_foreign_to_dictionary function would call pars_info_create but failed to call pars_info_free. (Bug #16754901)

InnoDB: The page_zip_validate() consistency check failed after compressing a page, in page_zip_compress(). This problem was caused by page_zip_decompress(), which failed to set heap_no correctly when a record contained no user data bytes. A record with no user data bytes occurs when, for example, a primary key is an empty string and all secondary index fields are NULL or an empty string. (Bug #16736929)

InnoDB: Some characters in the identifier for a foreign key constraint are modified during table exports. (Bug #16722314, Bug #69062)

InnoDB: During a transaction commit, prepare_commit_mutex is acquired to preserve the commit order. If the commit operation failed, the transaction would be rolled back but the mutex would not be released. Subsequent insert operations would not be able to acquire the same mutex. This fix frees prepare_commit_mutex during innobase_rollback. (Bug #16513588)

InnoDB: When the InnoDB shutdown mode (innodb_fast_shutdown) is set to 2 and the master thread enters the flush loop, the thread would not be able to exit under some circumstances. This could lead to a shutdown hang. (Bug #16411457)

InnoDB: After disabling foreign key checks with SET foreign_key_checks=0 and performing a DROP INDEX, the table was no longer accessible after restarting the server. This fix allows the table with missing foreign key indexes to be accessed when SET foreign_key_checks=0. When the table is accessible, the user must recreate the missing indexes to fulfill the foreign key constraints. (Bug #16208542, Bug #68148)

InnoDB: Successive deletes in descending key order would lead to under-filled InnoDB index pages. When an InnoDB index page is under-filled, it is merged with the left or right sibling node. The check performed to determine if a sibling node is available for merging was not functioning correctly. (Bug #68501, Bug #16417635)

InnoDB: Setting foreign_key_checks=0 and running ALTER TABLE to change the character set of foreign key columns for a database with multiple tables with foreign key constraints would leave the database in an inconsistent state. Subsequent ALTER TABLE operations (using the COPY algorithm) with foreign_key_checks=1 would fail due to the detected inconsistency. Reversion of the partially executed ALTER TABLE operation would also fail, resulting in the loss of the table being altered. When running the same ALTER TABLE operation with a RENAME clause, the inconsistency would not be detected but if the ALTER TABLE operation failed for some other reason, reversion of the partially executed ALTER TABLE failed with the same result.

The bug fix temporarily disables foreign_key_checks while the previous table definition is restored. (Bug #65701, Bug #14227431)

InnoDB: Creating a table with a comment or default textual value containing an apostrophe that is escaped with a backslash would sometimes cause the InnoDB storage engine to omit foreign key definitions. (Bug #61656, Bug #12762377)

InnoDB: The pthread_mutex, commit_threads_m, which was initialized but never used, has been removed from the code base. (Bug #60225, Bug #11829813)

Partitioning: When upgrading to MySQL 5.5.31 or higher, a message is written into the output of mysql_upgrade when encountering a partitioned table for which the ALGORITHM option is required to maintain binary compatibility with the original; the message includes the ALTER TABLE statement required to make the change. For such a table having a sufficiently large number of partitions, the message was truncated with an error before the complete ALTER TABLE statement could be written. (Bug #16589511)

Partitioning: When a range specified in the WHERE condition of a query against a table partitioned by RANGE entirely within that of one of the partitions, the next partition was also checked for rows although it should have been pruned away.

Suppose we have a range-partitioned table t created using the following SQL statement:

CREATE TABLE t  (
    id INT AUTO_INCREMENT,
    dt DATETIME,
    PRIMARY KEY (dt,id),
    UNIQUE KEY (id,dt)
)
    PARTITION BY RANGE  COLUMNS(dt) (
        PARTITION p0 VALUES LESS THAN ('2013-01-01'),
        PARTITION p1 VALUES LESS THAN ('2013-01-15'),
        PARTITION p2 VALUES LESS THAN ('2013-02-01'),
        PARTITION p3 VALUES LESS THAN ('2013-02-15'),
        PARTITION pmax VALUES LESS THAN (MAXVALUE)
);

An example of a query that exhibited this issue when run against t is shown here:

SELECT COUNT(*) FROM t
    WHERE dt >= '2013-02-01' AND dt < '2013-02-15';

In this case, partition pmax was checked, even though the range given in the WHERE clause lay entirely within partition p3. (Bug #16447483)

Partitioning: When dropping a partitioned table, the table's .par file was deleted first, before the table definition or data. This meant that, if the server failed during the drop operation, the table could be left in an inconsistent state in which it could neither be accessed nor dropped.

The fix for this problem makes the following changes:

(Bug #13548704, Bug #63884)

Replication: Some expressions employing variables were not handled correctly by LOAD DATA. (Bug #16753869)

Replication: Linker errors occurred if the header file log_event.h was included in an application containing multiple source files, because the file rpl_tblmap.cc was included in log_event.h. This fix moves the inclusion of rpl_tblmap.cc into the source files that use log_event.h. (Bug #16607258)

Installation of Solaris PKG packages could fail to execute mysql_install_db because it was invoked with the --random-passwords option (which does not exist until MySQL 5.6). (Bug #17160741)

Initialization of keycache_* variables (see Multiple Key Caches) during server startup could write to incorrect memory. (Bug #16945503)

Removing a server RPM package did not shut down the existing server if it was running. (Bug #16798868)

The code base was modified to account for new warning checks introduced by gcc 4.8. (Bug #16729109)

Upgrading from community SLES RPM packages to commercial packages for the same MySQL version failed with conflict errors. (Bug #16545296)

A user variable referenced during execution of a prepared statement is set to memory that is freed at the end of execution. A second execution of the statement could result in Valgrind warnings when accessing this memory. (Bug #16119355)

Misoptimization of left expressions in prepared statements could cause a server exit. (Bug #16095534)

Out-of-bounds reads could occur within filename_to_tablename(). (Bug #14834378)

When running a query on INFORMATION_SCHEMA.INNODB_BUFFER_PAGE that requested table_name and index_name values, query results would include index pages without table_name or index_name values. (Bug #14529666)

With the thread pool plugin in use, normal connection termination caused the Aborted_clients status variable to be incremented. (Bug #14081240)

MySQL Installer, if run in custom install or change mode, offered installation options that had no effect. (Bug #12928601)

Incorrect results could be returned from queries that used several aggr_func(DISTINCT) functions (where aggr_func() is an aggregate function such as COUNT()) when these referred to different columns of the same composite key. (Bug #12328597)

RPM source packages did not list libaio-devel as a dependency, causing builds to fail. (Bug #69158, Bug #16785036)

Comparison of a DATETIME value and a string did not work correctly for the utf8_unicode_ci collation. (Bug #68795, Bug #16567381)

mysqldump assumed the existence of the general_log and slow_log tables in the mysql database. It failed if invoked to dump tables from an older server where these tables do not exist. (Bug #65670, Bug #14236170)

Attempts to build from a source RPM package could fail because the build process attempted to refer to a pb2user that might not exist. (Bug #64641, Bug #13865797, Bug #69339, Bug #16874980)

A typo in cmake/dtrace.cmake prevented DTrace support from being enabled by -DENABLE_DTRACE-on. (Bug #60743, Bug #12325449)

Assigning the result of a subquery to a user variable raised an assertion when the outer query included DISTINCT and GROUP BY. (Bug #57196, Bug #11764371)

Functionality Added or Changed

Bugs Fixed

mysql_upgrade now verifies that the server version matches the version against which it was compiled, and exits if there is a mismatch. In addiion, a --version-check option permits specifying whether to enable version checking (the default), or disable checking if given as --skip-version-checking. (Bug #16500013)

Important Change; Replication: When the server was running with --binlog-ignore-db and SELECT DATABASE() returned NULL (that is, there was no currently selected database), statements using fully qualified table names in dbname.tblname format were not written to the binary log. This was because the lack of a currently selected database in such cases was treated as a match for any possible ignore option rather than for no such option; this meant that these statements were always ignored.

Now, if there is no current database, a statement using fully qualified table names is always written to the binary log. (Bug #11829838, Bug #60188)

InnoDB: When calling the lock_rec_block_validate() function after releasing the kernel mutex, there is a chance the lock might be invalid and result in a Valgrind error due to an invalid read on lock->index. This fix copies the lock->index when the kernel mutex is being held and passes the lock->index to lock_rec_block_validate(). (Bug #17022398, Bug #69413, Bug #16268289, Bug #68244)

InnoDB: After a clean shutdown, InnoDB does not check .ibd file headers at startup. As a result, in a crash recovery scenario, InnoDB could load a corrupted tablespace file. This fix implements consistency and status checks to avoid loading corrupted files. (Bug #16720368)

InnoDB: The page_zip_available function would count some fields twice. (Bug #16463505)

InnoDB: In debug builds, an insert failed with an invalid assertion: sync_thread_levels_g(array, level - 1, TRUE). (Bug #16409715)

InnoDB: Multiple concurrent calls to dict_update_statistics() would result in unnecessary server load. (Bug #16400412)

InnoDB: When tables are linked by foreign key constraints, loading one table would open other linked tables recursively. When numerous tables are linked by foreign key constraints, this would sometimes lead to a thread stack overflow causing the server to exit. Tables linked by foreign key constraints are now loaded iteratively. Cascade operations, which were also performed in a recursive manner, are now performed iteratively using an explicit stack. (Bug #16244691, Bug #65384)

InnoDB: When a transaction is in READ COMMITTED isolation level, gap locks are still taken in the secondary index when a row is inserted. This occurs when the secondary index is scanned for duplicates. The function row_ins_scan_sec_index_for_duplicate() always calls the function row_ins_set_shared_rec_lock() with LOCK_ORDINARY irrespective of the transaction isolation level. This fix modifies the row_ins_scan_sec_index_for_duplicate() function to call row_ins_set_shared_rec_lock() with LOCK_ORDINARY or LOCK_REC_NOT_GAP, based on the transaction isolation level. (Bug #16133801, Bug #68021)

InnoDB: Starting mysqld with --innodb_log_buffer_size=50GB failed to allocate memory and returned NULL. For non-debug builds there was no check in place and a segmentation fault occurred. This fix adds a log message stating that memory failed to be allocated, and adds an assertion. (Bug #16069598, Bug #68025)

InnoDB: When UNIV_DEBUG is enabled in debug builds, buf_validate() is often called which sometimes results in false alarms in tests on semaphore wait timeout. This fix increases counter values to reduce false alarms. (Bug #16068056)

InnoDB: The explain_filename function, which provides information about a partition by parsing the file name, would return an error when attempting to parse a file name with no partition information. (Bug #16051728)

InnoDB: An overflow would occur for innodb_row_lock_time_max and innodb_row_lock_current_waits. This fix modifies code logic in storage/innobase/srv/srv0srv.c. (Bug #16005310)

InnoDB: For UPDATE statements in which an error occurred, it was possible for a temporary file opened during the update not to be closed. (Bug #15978766)

Replication: Point-in-time recovery could fail when trying to restore a single database from a binary log in row-based format using mysqlbinlog with the --database option. (Bug #16698172)

Replication: When used with the options --dump-slave --include-master-host-port, mysqldump printed the port number within quotation marks, as if it were a string value rather than an integer. (Bug #16615117)

Replication: Running the server with --log-slave-updates together with --replicate-wild-ignore-table or --replicate-ignore-table in some cases caused updates to user variables not to be logged. (Bug #16541422)

Replication: Following disconnection from the master, the slave could under certain conditions report erroneously on reconnection that it had received a packet that was larger than slave_max_allowed_packet, causing replication to fail. (Bug #16438800, Bug #68490)

Replication: When semisynchronous replication was enabled, the automatic dropping on the master of an event created using ON COMPLETION NOT PRESERVE caused the master to fail. (Bug #15948818, Bug #67276)

Replication: Setting a SET column to NULL inside a stored procedure caused replication to fail. (Bug #14593883, Bug #66637)

Replication: The binary log contents got corrupted sometimes, because the function MYSQL_BIN_LOG::write_cache always thought it had reached the end-of-cache when the function my_b_fill() reported a '0,' while that could also mean an error had occurred. This fix makes sure that whenever my_b_fill() returns a '0,' an error check is performed on info->error. (Bug #14324766, Bug #60173)

Replication: When replicating to a BLACKHOLE table using the binary logging format, updates and deletes cannot be applied and so are skipped. Now a warning is generated for this whenever it occurs.

(Bug #13004581)

The WKB reader for spatial operations could fail and cause a server exit. (Bug #16451878)

For debug builds, DBUG_EXPLAIN resulted in a buffer overflow when the debug system variable value was more than 255 characters. (Bug #16402143)

Several scripts in the sql-bench directory that were supposed to be executable did not have the executable access bit set. (Bug #16395606)

EXPORT_SET() or MAKE_SET() with many COUNT(*) arguments could cause a server exit. (Bug #16359402)

For debug builds, GROUP_CONCAT(... ORDER BY) within an ORDER BY clause could cause a server exit. (Bug #16347426)

A GROUP_CONCAT() invocation containing subquery having an outer reference caused the server to exit. (Bug #16347343)

thread_pool_high_priority_connection could not be set at server startup. (Bug #16310373)

Oracle RPM packages were unusable by yum due to issues with the obsoletes line in the .spec file causing yum to interpret the package as obsoleting itself. (Bug #16298542)

If loose index scan was used on a query that used MIN(), a segmentation fault could occur. (Bug #16222245)

If multiple statements were sent in a single request, the audit log plugin logged only the last one. Now it logs each statement separately. (Bug #16169063)

A prepared statement that used GROUP_CONCAT() and an ORDER BY clause that named multiple columns could cause the server to exit. (Bug #16075310)

ORDER BY MATCH ... AGAINST could cause a server exit. (Bug #16073689)

The mysql.server script exited with an error if the status command was executed with multiple servers running. (Bug #15852074)

A query with a union and a join could crash the parser. (Bug #14786792, Bug #16076289)

When processing row-based-replication events in the old binary log format from prior to MySQL 5.1 GA builds, mysqlbinlog could result in out-of-bounds heap buffer reads and undefined behaviour. (Bug #14771299)

Installation using Solaris packages ran mysql_install_db during upgrade operations (this should occur only for new installations). (Bug #14747671, Bug #16534721)

The mysql client allocated but did not free a string after reading each line in interactive mode, resulting in a memory leak. (Bug #14685362)

INSERT ... ON DUPLICATE KEY UPDATE on a view could cause a server exit. (Bug #14261010)

Grouping by an outer BLOB column in a subquery caused a server exit. (Bug #13966809, Bug #14700180)

The server could exit due to improper handling of the error from an invalid comparison. (Bug #13009341)

The CMake check for unsigned time_t failed on all platforms. (Bug #11766815)

If an UPDATE containing a subquery caused a deadlock inside InnoDB, the deadlock was not properly handled by the SQL layer. The SQL layer then tried to unlock the row after InnoDB rolled back the transaction, raising an assertion inside InnoDB. (Bug #69127, Bug #16757869)

MD5() code did not properly initialize one of its data structures. (Bug #68909, Bug #16626742)

When specified in an option file, the plugin-dir client option was ignored. (Bug #68800, Bug #16680313)

Using range access with an index prefix could produce incorrect results. (Bug #68750, Bug #16540042)

If Loose Index Scan was used to evaluate a query that compared an integer column to an integer specified as a quoted string (for example, col_name = '1'), the query could return incorrect results. (Bug #68473, Bug #16394084)

MySQL Configuration Wizard did not anticipate existing files from a previous MySQL install operation, causing it to fail starting the MySQL service. (Workaround: Manually delete MySQL data in the ProgramData folder.) (Bug #62106, Bug #16777237)

The url columns in the mysql datatbase help tables were too short to hold some of the URLs in the help content. For new installations, these columns are now created as type TEXT to accommodate longer URLs.

For upgrades, mysql_upgrade does not update the columns. Modify them manually using these statements:

ALTER TABLE mysql.help_category MODIFY url TEXT NOT NULL;
ALTER TABLE mysql.help_topic MODIFY url TEXT NOT NULL;

(Bug #61520, Bug #12671635)

It is now possible to suppress installation of the mysql-test directory after compiling MySQL from source by invoking CMake with the INSTALL_MYSQLTESTDIR option explicitly set to empty:

cmake . -DINSTALL_MYSQLTESTDIR=

Previously, attempts to do this resulted in an error. (Bug #58615, Bug #11765629)

On 64-bit OS X systems, CMake used x86 rather than x86_64 when determining the machine type. (Bug #58462, Bug #11765489)

The parser rejected legal queries that involved a UNION where the right hand side query term has a table in parenthese. (Bug #54382, Bug #11761854)

IF() function evaluations could produce different results when executed in a prepared versus nonprepared statement. (Bug #45370, Bug #11753852)

RPM Notes

Functionality Added or Changed

Bugs Fixed

It was not possible to upgrade a community RPM to a commercial RPM using rpm -uvh or yum localupdate. To deal with this, the RPM spec file has been updated in MySQL 5.5.31, which has the following consequences:

Additional details follow.

For a non-upgrade installation of MySQL 5.5.31, it is possible to install using yum:

shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm

For upgrades to MySQL 5.5.31, the upgrade is performed by removing the old installation and installing the new one. To do this, use the following procedure:

Alternatively, the removal and installation can be done using yum:

shell> yum remove MySQL-server-OLDVERSION.glibc23.i386.rpm
shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm

(Bug #16445097, Bug #16445125, Bug #16587285)

MySQL no longer uses the default OpenSSL compression. (Bug #16235681)

Performance; InnoDB: Performance was improved for operations on tables with many rows that were deleted but not yet purged. The speedup applies mainly to workloads that perform bulk deletes, or updates to the primary key columns, and where the system is busy enough to experience purge lag. (Bug #16138582, Bug #68069)

Performance; InnoDB: The DROP TABLE statement for a table using compression could be slower than necessary, causing a stall for several seconds. MySQL was unnecessarily decompressing pages in the buffer pool related to the table as part of the DROP operation. (Bug #16067973)

Incompatible Change; Partitioning: Changes in the KEY partitioning hashing functions used with numeric, date and time, ENUM, and SET columns in MySQL 5.5 makes tables using partitioning or subpartitioning by KEY on any of the affected column types and created on a MySQL 5.5 or later server incompatible with a MySQL 5.1 server. This is because the partition IDs as calculated by a MySQL 5.5 or later server almost certainly differ from those calculated by a MySQL 5.1 server for the same table definition and data as a result of the changes in these functions.

The principal changes in the KEY partitioning implementation in MySQL 5.5 resulting in this issue were as follows: 1. The hash function used for numeric and date and time columns changed from binary to character-based. 2. The base used for hashing of ENUM and SET columns changed from latin1 ci characters to binary.

The fix involves adding the capability in MySQL 5.5 and later to choose which type of hashing to use for KEY partitioning, which is implemented with a new ALGORITHM extension to the PARTITION BY KEY option for CREATE TABLE and ALTER TABLE. Specifying PARTITION BY KEY ALGORITHM=1 ([columns]) causes the server to use the hashing functions as implemented in MySQL 5.1; using ALGORITHM=2 causes the server to use the hashing functions from MySQL 5.5 and later. ALGORITHM=2 is the default. Using the appropriate value for ALGORITHM, you can perform any of the following tasks:

This syntax is not backward compatible, and causes errors in older versions of the MySQL server. When generating CREATE TABLE ... PARTITION BY KEY statements, mysqldump brackets any occurrence of ALGORITHM=1 or ALGORITHM=2 in conditional comments such that it is ignored by a MySQL server whose version is not at least 5.5.31. An additional consideration for upgrades is that MySQL 5.6 servers prior to MySQL 5.6.11 do not ignore the ALGORITHM option in such statements when generated by a MySQL 5.5 server, due to the that the conditional comments refer to version 5.5.31; in this case, you must edit the dump manually and remove or comment out the option wherever it occurs before attempting to load it into a MySQL 5.6.10 or earlier MySQL 5.6 server. This is not an issue for dumps generated by MySQL 5.6.11 or later version of mysqldump, where the version used in such comments is 5.6.11. For more information, see ALTER TABLE Partition Operations.

As part of this fix, a spurious assertion by InnoDB that a deleted row had previously been read, causing the server to assert on delete of a row that the row was in the wrong partition, was also removed. (Bug #14521864, Bug #66462, Bug #16093958, Bug #16274455)

References: See also: Bug #11759782.

Important Note; Replication: Using row-based logging to replicate from a table to a same-named view led to a failure on the slave. Now, when using row-based logging, the target object type is checked prior to performing any DML, and an error is given if the target on the slave is not actually a table.

(Bug #11752707, Bug #43975)

InnoDB: Crash recovery failed with a !recv_no_log_write assertion when reading a page. (Bug #16405422)

InnoDB: For InnoDB tables, if a PRIMARY KEY on a VARCHAR column (or prefix) was empty, index page compression could fail. (Bug #16400920)

InnoDB: RENAME TABLE would result in a hang due to a MySQL mutex acquisition deadlock. (Bug #16305265)

InnoDB: For debug builds, InnoDB status exporting was subject to a race condition that could cause a server exit. (Bug #16292043)

InnoDB: InnoDB now aborts execution on Windows by calling the abort() function directly, as it does on other platforms. (Bug #16263506)

InnoDB: Internal read operations could be misclassified as synchronous when they were actually asynchronous. When the I/O requests returned sooner than expected, threads could be scheduled inefficiently. This issue mainly affected read-ahead requests, and thus had relatively little impact on I/O performed by user queries. (Bug #16249505, Bug #68197)

InnoDB: If the MySQL server halted at a precise moment when a purge operation was being applied from the change buffer, the operation could be incorrectly performed again during the next restart. A workaround was to set the configuration option innodb_change_buffering=changes, to turn off change buffering for purge operations. (Bug #16183892, Bug #14636528)

InnoDB: Arithmetic underflow during page compression for CREATE TABLE on an InnoDB table could cause a server exit. (Bug #16089381)

InnoDB: If the server was started with the skip-innodb option, or InnoDB otherwise failed to start, query any of these Information Schema tables would cause a severe error:

(Bug #14144290)

InnoDB: When printing out long semaphore wait diagnostics, sync_array_cell_print() ran into a segmentation violation (SEGV) caused by a race condition. This fix addresses the race condition by allowing the cell to be freed while it is being printed. (Bug #13997024)

InnoDB: Killing a query caused an InnoDB assertion failure when the same table (cursor) instance was used again. This is the result of a regression error introduced by the fix for Bug#14704286. The fix introduced a check to handle kill signals for long running queries but the cursor was not restored to the proper state. (Bug #68051, Bug #16088883)

InnoDB: The length of internally generated foreign key names was not checked. If internally generated foreign key names were over the 64 character limit, this resulted in invalid DDL from SHOW CREATE TABLE. This fix checks the length of internally generated foreign key names and reports an error message if the limit is exceeded. (Bug #44541, Bug #11753153)

Partitioning: A query on a table partitioned by range and using TO_DAYS() as a partitioing function always included the first partition of the table when pruning. This happened regardless of the range employed in the BETWEEN clause of such a query. (Bug #15843818, Bug #49754)

Partitioning: Execution of ALTER TABLE ... DROP PARTITION against a view caused the server to crash, rather than fail with an error as expected. (Bug #14653504)

Replication: A zero-length name for a user variable (such as @``) was incorrectly considered to be a sign of data or network corruption when reading from the binary log. (Bug #16200555, Bug #68135)

Replication: Backtick (`) characters were not always handled correctly in internally generated SQL statements, which could sometimes lead to errors on the slave. (Bug #16084594, Bug #68045)

References: This issue is a regression of: Bug #14548159, Bug #66550.

Replication: Using the --replicate-* options (see Replication Slave Options and Variables) could in some cases lead to a memory leak on the slave. (Bug #16056813, Bug #67983)

Replication: It was possible in certain cases—immediately after detecting an EOF in the dump thread read event loop, and before deciding whether to change to a new binary log file—for new events to be written to the binary log before this decision was made. If log rotation occurred at this time, any events that occurred following EOF detection were dropped, resulting in loss of data. Now in such cases, steps are taken to make sure that all events are processed before allowing the log rotation to take place. (Bug #13545447, Bug #67929)

References: See also: Bug #16016886.

SHOW ENGINE PERFORMANCE_SCHEMA STATUS could report incorrect memory-allocation values when the correct values exceeded 4GB. (Bug #16414644)

The server could exit if a prepared statement attempted to create a table using the name of an existing view while an SQL handler was opened. (Bug #16385711)

A long database name in a GRANT statement could cause the server to exit. (Bug #16372927)

On Linux, a race condition involving epoll() could cause the thread pool plugin to miss events. This was most likely on systems with greater than 16 cores. (Bug #16367483)

Incorrect results were returned if a query contained a subquery in an IN clause which contained an XOR operation in the WHERE clause. (Bug #16311231)

For upgrade operations, RPM packages produced unnecessary errors about being unable to access .err files. (Bug #16235828)

yaSSL did not perform proper padding checks, but instead examined only the last byte of cleartext and used it to determine how many bytes to remove. (Bug #16218104)

Invocation of the range optimizer for a NULL select caused the server to exit. (Bug #16192219)

With the thread pool plugin enabled, large numbers of connections could lead to a Valgrind panic or failure of clients to be able to connect. (Bug #16088658, Bug #16196591)

The initial test database contained a dummy.bak file that prevented DROP DATABASE from working. This file is no longer included. Also, a db.opt file is now included that contains these lines:

default-character-set=latin1
default-collation=latin1_swedish_ci

(Bug #16062056)

Issuing a PREPARE statement using certain combinations of stored functions and user variables caused the server to exit. (Bug #16056537)

Setting a system variable to DEFAULT could cause the server to exit. (Bug #16044655)

When a partition is missing, code in ha_innodb.cc would retry 10 times and sleep for a microsecond each time while holding LOCK_open. The retry logic for partitioned tables was introduced as a fix for Bug#33349 but did not include a test case to validate it. This fix removes the retry logic for partitioned tables. If the problem reported in Bug#33349 reappears, a different solution will be explored. (Bug #15973904)

Contention in the thread pool during kill processing could lead to a Valgrind panic. (Bug #15921866)

The MSI Installer installed MySQL in “per-user” mode, which could result in conflicts or failure to detect an existing installation if two users installed MySQL on the same machine. Now the MSI Installer uses “per-machine” installation mode. (Bug #14711808)

When a client program loses the connection to the MySQL server or if the server begins a shutdown after the client has executed mysql_stmt_prepare(), the next mysql_stmt_prepare() returns an error (as expected) but subsequent mysql_stmt_execute() calls crash the client. (Bug #14553380)

SHOW COLUMNS on a view defined as a UNION of Geometry columns could cause the server to exit. (Bug #14362617)

A LIKE pattern with too many '%' wildcards could cause a segmentation fault. (Bug #14303860)

SET var_name = VALUES(col_name) could cause the server to exit. This syntax is now prohibited because in SET context there is no column name and the statement returns ER_BAD_FIELD_ERROR. (Bug #14211565)

The COM_CHANGE_USER command in the client/server protocol did not properly use the character set number in the command packet, leading to incorrect character set conversion of other values in the packet. (Bug #14163155)

On Microsoft Windows, the MSI package would now allow a license switch (community to or from the commercial edition) when the switched MySQL Server versions were identical. (Bug #13071597)

Subqueries with OUTER JOIN could return incorrect results if the subquery referred to a column from another SELECT. (Bug #13068506)

mysql_install_db did not escape '_' in the host name for statements written to the grant tables. (Bug #11746817)

CMake did not check whether the system zlib had certain functions required for MySQL, resulting in build errors. Now it checks and falls back to the bundled zlib if the functions are missing. (Bug #65856, Bug #14300733)

If a dump file contained a view with one character set and collation defined on a view with a different character set and collation, attempts to restore the dump file failed with an “illegal mix of collations” error. (Bug #65382, Bug #14117025)

Incorrect metadata could be produced for columns returned from some views. (Bug #65379, Bug #14096619)

If the server was started without a --datadir option, SHOW VARIABLES could show an empty value for the datadir system variable. (Bug #60995, Bug #12546953)

For debug builds, some queries with SELECT ... FROM DUAL nested subqueries raised an assertion. (Bug #60305, Bug #11827369)

UNION ALL on BLOB columns could produce incorrect results. (Bug #50136, Bug #11758009)

An out-of-memory condition could occur while handling an out-of-memory error, leading to recursion in error handling. (Bug #49514, Bug #11757464)

The REPLACE() function produced incorrect results when a user variable was supplied as an argument and the operation was performed on multiple rows. (Bug #49271, Bug #11757250)

Setting max_connections to a value less than the current number of open connections caused the server to exit. (Bug #44100, Bug #11752803)

The optimizer used loose index scan for some queries for which this access method is inapplicable. (Bug #42785, Bug #11751794)

View access in low memory conditions could raise a debugging assertion. (Bug #39307, Bug #11749556)

Functionality Added or Changed

Bugs Fixed

InnoDB: When compressed tables were used, the calculation to compute memory usage within the buffer pool was complex because the compressed pages could be smaller than 16KB or the user-specified page size. Although this information can be retrieved from the INFORMATION_SCHEMA.INNODB_BUFFER_PAGE table, that operation is expensive. The following new status variables help to simplify calculations involving buffer pool memory usage:

(Bug #15842637)

InnoDB: The innodb_print_all_deadlocks configuration option from MySQL 5.6 was backported to MySQL 5.5. This option records each deadlock condition in the MySQL error log, allowing easier troubleshooting if frequent deadlocks point to application coding issues. (Bug #14515889)

In RPM packages built for Unbreakable Linux Network, libmysqld.so now has a version number. (Bug #15972480)

Performance; InnoDB: Some data structures related to undo logging could be initialized unnecessarily during a query, although they were only needed under specific conditions. (Bug #14676084)

Performance; InnoDB: Optimized read operations for compressed tables by skipping redundant tests. The check for whether any related changes needed to be merged from the insert buffer was being called more often than necessary. (Bug #14329288, Bug #65886)

Performance; InnoDB: Immediately after a table was created, a query against it would not use a loose index scan. The same query might use a loose index scan following an ALTER TABLE on the table. The fix improves the accuracy of the cost estimate for queries involving the grouping functions min() and max(), and prevents the query plan from being changed by the ALTER TABLE statement. (The more stable query plan might or might not use a loose index scan.) (Bug #14200010)

InnoDB; Partitioning: Previously, when attempting to optimize one or more partitions of a partitioned table that used a storage engine that does not support partition-level OPTIMIZE, such as InnoDB, MySQL reported Table does not support optimize, doing recreate + analyze instead, then re-created the entire table, but did not actually analyze it. Now in such cases, the warning message is, Table does not support optimize on partitions. All partitions will be rebuilt and analyzed. In addition, the entire table is analyzed after first being rebuilt. (Bug #11751825, Bug #42822)

InnoDB: On systems that cannot handle unaligned memory access, depending on the stack frame alignment, a SIGBUS error could occur during startup. This issue was observed on Solaris 64-bit systems. (Bug #16021177)

InnoDB: Creating an index on a CHAR column could fail for a table with a character set with varying length, such as utf8, if the table was created with the ROW_FORMAT=REDUNDANT clause. (Bug #15874001)

InnoDB: The status variable Innodb_buffer_pool_read_ahead_evicted could show an inaccurate value, higher than expected, because some pages in the buffer pool were incorrectly considered as being brought in by read-ahead requests. (Bug #15859402, Bug #67476)

InnoDB: The server could halt with an assertion error when creating an index on a column prefix for a column using a multibyte character set:

InnoDB: Assertion failure in thread thread_num in file row0merge.cc line 465
InnoDB: Failing assertion: len == ifield-<fixed_len

(Bug #14753402)

InnoDB: The server could halt with an assertion error while creating an index:

InnoDB: Assertion failure in thread thread_num in file row0merge.cc line 465

This issue affected tables with a combination of ROW_FORMAT=REDUNDANT off-page columns, and an index on a column prefix. (Bug #14753402)

InnoDB: A regression introduced by the fix for Bug#14100254 would result in a “!BPAGE->FILE_PAGE_WAS_FREED” assertion. (Bug #14676249)

InnoDB: If the server crashed at a precise moment during an ALTER TABLE operation that rebuilt the clustered index for an InnoDB table, the original table could be inaccessible afterward. An example of such an operation is ALTER TABLE ... ADD PRIMARY KEY The fix preserves the original table if the server halts during this operation. You might still need to rename the .ibd file manually to restore the original table contents: in MySQL 5.6 and higher, rename from #sql-ib$new_table_id.ibd to table_name.ibd within the database directory; prior to MySQL 5.6, the temporary file to rename is table_name#1 or #2. (Bug #14669848)

InnoDB: An error at the filesystem level, such as too many open files, could cause an unhandled error during an ALTER TABLE operation. The error could be accompanied by Valgrind warnings, and by this assertion message:

Assertion `! is_set()' failed.
mysqld got signal 6 ;

(Bug #14628410, Bug #16000909)

InnoDB: A RENAME TABLE statement could stall for several minutes before timing out. This issue could occurred for a table using compression, with change buffering enabled. (Bug #14556349)

InnoDB: A DML operation performed while a RENAME TABLE operation waits for pending I/O operations on the tablespace to complete would result in a deadlock. (Bug #14556349)

InnoDB: During shutdown, with the innodb_purge_threads configuration option set greater than 1, the server could halt prematurely with this error:

mysqld got signal 11

A workaround was to increase innodb_log_file_size and set innodb_purge_threads=1. The fix was backported to MySQL 5.5 and 5.1, although those versions do not have the innodb_purge_threads configuration option so the error was unlikely to occur. (Bug #14234028)

InnoDB: If the value of innodb_force_recovery was less than 6, opening a corrupted table might loop forever if a corrupted page was read when calculating statistics for the table. Information about the corrupted page was written repeatedly to the error log, possibly causing a disk space issue. The fix causes the server to halt after a fixed number of failed attempts to read the page. To troubleshoot such a corruption issue, set innodb_force_recovery=6 and restart. (Bug #14147491, Bug #65469)

InnoDB: The value of the innodb_version variable was not updated consistently for all server releases for the InnoDB Plugin in MySQL 5.1, and the integrated InnoDB component in MySQL 5.5, 5.6, and higher. Since InnoDB and MySQL Server development cycles are fully integrated and synchronized, now the value returned by the innodb_version variable is the same as for the version variable. (Bug #13463493, Bug #63435)

Partitioning: Concurrent ALTER TABLE ... REBUILD PARTITION operations could interfere with one another, even when not running against the same table, because they both used global memory for storage. Now each partition rebuild operation stores intermediate data in memory that is local to that process. (Bug #14589559, Bug #66645)

Partitioning: Inserting any number of rows into an ARCHIVE table that used more than 1000 partitions and then attempting to drop the table caused the MySQL Server to fail. (Bug #13819630, Bug #64580)

Replication: When a binary log is replayed on a server (for example, by executing a command like mysqlbinlog binlog.000001 | mysql), it sets a pseudo-slave mode on the client connection used, so that the server can read binary log and apply binary log events correctly. However, the pseudo-slave mode was not disabled after the binary log dump was read, which caused unexpected filtering rules to be applied to SQL statements subsequently executed on the same connection. (Bug #15891524)

Replication: After dropping a column from the slave's version of a table, then altering the same column of this table on the master (so that a type conversion would have been required had the column not been droppped on the slave), inserts into this table caused replication to fail. (Bug #15888454)

Replication: When using statement-based replication, and where the master and the slave used table schemas having different AUTO_INCREMENT columns, inserts generating AUTO_INCREMENT values logged for a given table on the master could be applied to the wrong table on the slave. (Bug #12669186)

Replication: Repeated execution of CHANGE MASTER TO statements using invalid MASTER_LOG_POS values could lead to errors and possibly a crash on the slave. Now in such cases, the statement fails with a clear error message. (Bug #11764602, Bug #57454)

Replication: If the disk becomes full while writing to the binary log, the server hangs until space is freed up manually. It was possible after this was done for the MySQL server to fail, due to an internal status value being set when not needed. Now in such cases, rather than trying to set this status, a warning is written in the error log instead. (Bug #11753923, Bug #45449)

Microsoft Windows: Dynamic file names (with colons) are no longer allowed. Static file names using the Alternate Data Stream (ADS) NTFS functionality of Microsoft Windows may continue to be used. (Bug #11761752)

Directory name manipulation could result in stack overflow on OS X and Windows. (Bug #16066243)

Joins of exactly 32 tables and containing a HAVING clause returned an empty result. (Bug #15972635)

A buffer-handling problem in yaSSL was fixed. (Bug #15965288)

A mysys library string-formatting routine could mishandle width specifiers. (Bug #15960005)

Metadata locking and table definition cache routines did not always check length of names passed to them. (Bug #15954872)

In certain cases, UpdateXML() could return NULL incorrectly. (Bug #15948580)

References: See also: Bug #13007062.

XA START had a race condition that could cause a server crash. (Bug #14729757)

Enabling the query cache during high client contention could cause the server to exit. (Bug #14727815)

There was a performance regression for queries using SELECT ... INTO user variables and a WHERE condition on one or more of the variables in the INTO list. (Bug #14664077)

References: This issue is a regression of: Bug #12408412.

The server sometimes failed to respect MAX_CONNECTIONS_PER_HOUR limits on user connections. (Bug #14627287)

Output generated with mysqldump --routines could produce syntax errors when reloaded. (Bug #14463669)

With the thread pool plugin installed, a workload consisting of concurrent KILL statements and ping queries caused the server to exit. (Bug #14458232, Bug #14458002)

CHECK TABLE and REPAIR TABLE could crash if a MyISAM table had a corrupt key (.MYI) file. Now the server produces an error. (Bug #13556107, Bug #13556000)

Passing an unknown time zone specification to CONVERT_TZ() resulted in a memory leak. (Bug #12347040)

Configuring the server with performance_schema_events_waits_history_size=0 and performance_schema_events_waits_history_long_size=0 could cause a Performance Schema segmentation fault. (Bug #68008, Bug #16060864)

mysqld_safe used the nonportable -e test construct. (Bug #67976, Bug #16046140)

For subqueries executing using a filesort, the optimizer could produce an incorrect result containing wrong rows. (Bug #66845, Bug #14636211)

References: See also: Bug #12667154.

The mysql client could mishandle the delimiter command if it occurred on a line during which mysql was looking for the end of a quoted string. (Bug #64135, Bug #13639125)

For dumps of the mysql database, mysqldump skips the event table unless the --events option is given. mysqldump now prints a warning if invoked without --events that the mysql.event table is not dumped without that option. (Bug #55587, Bug #11762933)

For MEMORY tables with HASH indexes, DELETE sometimes failed to delete all applicable rows. (Bug #51763, Bug #11759445)

UNION type conversion could incorrectly turn unsigned values into signed values. (Bug #49003, Bug #11757005)

DECIMAL multiplication operations could produce significant inaccuracy. (Bug #45860, Bug #11754279)

During the startup process, mysqld could incorrectly remove the PID file of an already running mysqld. (Bug #23790, Bug #11746142)

References: See also: Bug #14726272.

Functionality Added or Changed

Bugs Fixed

The SHOW AUTHORS and SHOW CONTRIBUTORS statements are now deprecated in MySQL 5.5 and have been removed in MySQL 5.6.

Performance; InnoDB: The timing values for low-level InnoDB read operations were adjusted for better performance with fast storage devices, such as SSD. This enhancement primarily affects read operations for BLOB columns in compressed tables. (Bug #13702112, Bug #64258)

Incompatible Change: LAST_INSERT_ID(expr) did not work for expr values greater than the largest signed BIGINT value. Such arguments now are accepted, with some consequences for compatibility with previous versions:

(Bug #20964, Bug #11745891)

Important Change; InnoDB: A DML statement using the index merge access method could lock many rows from the table, even when those rows were not part of the final result set. This fix reduces the excessive locking by releasing the locks of unmatched rows. This optimization affects only transactions with isolation level equal to or less strict than READ COMMITTED; it does not apply to transactions using REPEATABLE READ or SERIALIZABLE isolation level. (Bug #14226171)

InnoDB: An online DDL operation for an InnoDB table incorrectly reported an empty value ('') instead of the correct key value when it reported a duplicate key error for a unique index using an index prefix. (Bug #14729221)

InnoDB: If a CREATE TABLE statement failed due to a disk full error, some memory allocated during the operation was not freed properly. (Bug #14708715)

InnoDB: This fix makes MySQL more responsive to KILL QUERY statements when the query is accessing an InnoDB table. (Bug #14704286)

InnoDB: If the server crashed at the specific point when a change buffer entry was being merged into a buffer pool page, the transaction log and the change buffer were left in an inconsistent state. After a restart, MySQL could crash after reading the corresponding secondary index page. The problem was more likely to occur in MySQL 5.5 or later, where the original insert buffering mechanism was generalized to cover other operations. (Bug #14636528, Bug #66819, Bug #58571, Bug #61104, Bug #65443)

InnoDB: With the innodb_file_per_table setting enabled, a DROP TABLE operation could cause a crash, due to a race condition that depended on the timing of pending I/O requests. (Bug #14594600, Bug #66718)

InnoDB: If a table was defined with an index key length very close to the upper length limit of 3072, a query against that table could cause a serious error. (Bug #14500557, Bug #14537695)

InnoDB: When an auto-increment column used a FLOAT or DOUBLE data type, if the auto-increment value became very large (larger than the maximum unsigned long long value), subsequent inserts could fail or cause the server to halt. (Bug #14145950, Bug #55071)

InnoDB: If a transaction was started with a consistent snapshot, then new indexes were added to the table while the transaction was in progress, a subsequent UPDATE statement could incorrectly encounter the error:

ER_TABLE_DEF_CHANGED: insufficient history for index

This issue could cause an assertion error in debug builds. (Bug #14036214)

InnoDB: The error message was improved for the case where an UPDATE failed because the row included several BLOB values greater than 768 bytes each, causing the size of a row to exceed half the page size. The old message, was misleading; it suggested using BLOBs, when the 768-byte prefix for each BLOB column was the cause of the limit error:

Error Code 1118: Row size too large. The maximum row size for the used table
type, not counting BLOBs, is 8126. You have to change some columns to TEXT or
BLOBs

A workaround for the problem was to create the table with the ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED clause, which is now suggested in the message. (Bug #13453036, Bug #63507)

InnoDB: In rare circumstances, MySQL could apply InnoDB undo records out of order during a ROLLBACK of an operation that modified a BLOB column. This issue could cause an assertion error in debug builds:

!bpage->file_page_was_freed

(Bug #13249921)

InnoDB: In debug builds, a mismatch in the InnoDB PAGE_FREE list would cause an assertion. (Bug #12701488)

Replication: Updates writing user variables whose values were never set on a slave while using --replicate-ignore-table could cause the slave to fail. (Bug #14597605)

References: This issue is a regression of: Bug #14275000.

Replication: Following an insert into a nontransactional table that failed due to insufficient disk space, the server did not properly clean up all pending events, leading to an assert or possibly to other errors. (Bug #11750014)

Replication: Backtick (`) characters were not always handled correctly in internally generated SQL statements, which could sometimes lead to errors on replication slaves or cause failure of restore operations from binary log files. (Bug #66550, Bug #14548159, Bug #29422, Bug #11746883)

Within a stored procedure, executing a multiple-table DELETE statement that used a very long table alias could cause the server to exit. (Bug #15954896)

Very long table aliases in queries could cause the server to exit. (Bug #15948123)

Very long database names in queries could cause the server to exit. (Bug #15912213, Bug #16900358)

Attempting to create an auto-increment column in an InnoDB table with a NULL type attribute could cause a serious error. (Bug #14758479)

A DELETE statement for an InnoDB table could write incorrect transaction metadata into a record, causing the server to halt with an error. To work around this issue, reduce the specified length of the primary key to less than 1K bytes. (Bug #14731482)

Repeated execution of a query containing a subquery that used MAX() could result in increasing memory consumption. (Bug #14683676)

USE dbname could fail with Unknown database when dbname contained multiple backtick (`) characters. (Bug #14645196)

Within a stored program, memory allocated to hold condition information was not released until program exit, leading to excessive memory use. (Bug #14640599)

SHOW PROFILE could be used to cause excessive server memory consumption. (Bug #14629232)

The thread cache implementation worked in LIFO rather than FIFO fashion and could result in a thread being denied service (although this was a remote possibility). (Bug #14621627)

The configure.pl script that converts GNU configure options to CMake equivalents generated erroneous output for the --with-client-ldflags and --with-mysqld-ldflags options. It now ignores those options. (Bug #14593123)

Improper memory cleanup could cause the server to exit. (Bug #14536113)

Granting or revoking the PROXY privilege caused the server to exit if the server was started with --skip-name-resolve. (Bug #14211140)

CREATE USER and DROP USER could fail to flush the privileges, requiring FLUSH PRIVILEGES to be used explicitly. (Bug #13864642)

Access to INFORMATION_SCHEMA tables through a view could leak memory. (Bug #13734987)

A memory leak could occur for queries containing a subquery that used GROUP BY on an outer column. (Bug #13724099)

On Microsoft Windows with CMake 2.6, the build process would not stop if the create_initial_db step failed. (Bug #13713525)

CHECK TABLE and REPAIR TABLE could crash if a MyISAM table had a corrupt key (.MYI) file. Now the server produces an error. (Bug #13556441)

The test in mysqld_safe for the presence of the --plugin_dir option and assignment of a default value to it were performed before the actual argument parsing took place. (Bug #13548161)

Improper memory cleanup could cause the server to exit. (Bug #13340270)

A memory leak occurred due to failure to clean up after QUICK_INDEX_MERGE_SELECT/Unique. (Bug #12694872, Bug #14542543)

A “buffer too small” error message from the myisamchk command referred to the myisam_sort_buffer_size configuration option, when it should have referred to sort_buffer_size.

myisamchk now has a myisam_sort_buffer_size variable available as an alternative name to sort_buffer_size. myisam_sort_buffer_size is preferable to sort_buffer_size because its name corresponds to the myisam_sort_buffer_size server system variable that has a similar meaning. sort_buffer_size should be considered deprecated. (Bug #11754894, Bug #46578)

The number of connection errors from a given host as counted by the server was periodically reset, with the result that max_connect_errors was never reached and invalid hosts were never blocked from trying to connect. (Bug #11753779)

References: See also: Bug #38247, Bug #43006, Bug #45584, Bug #45606.

RHEL RPM packages had a conflict between mysql-libs and mysql-shared. (Bug #67965, Bug #16041010)

In debug builds, an InnoDB assertion was overly aggressive about prohibiting an open range. (Bug #66513, Bug #14547952)

On Windows, the Perl version of mysql_install_db created system tables in the mysql database that were not populated properly. (Bug #65584, Bug #14181049)

mysqld_safe ignored the value of the UMASK environment variable, leading to behavior different from mysqld with respect to the access mode of created files. Now mysqld_safe (and mysqld_multi) attempt to approximate the same behavior as mysqld. (Bug #57406, Bug #11764559)

During optimization, ZEROFILL values may be converted to string constants. However, CASE expressions did not handle switching data types after the planning stage, leading to CASE finding a null pointer instead of its argument. (Bug #57135, Bug #11764313)

Audit Log Notes

Functionality Added or Changed

Bugs Fixed

MySQL Enterprise Edition now includes MySQL Enterprise Audit, implemented using a server plugin named audit_log. MySQL Enterprise Audit uses the open MySQL Audit API to enable standard, policy-based monitoring and logging of connection and query activity executed on specific MySQL servers. Designed to meet the Oracle audit specification, MySQL Enterprise Audit provides an out of box, easy to use auditing and compliance solution for applications that are governed by both internal and external regulatory guidelines.

When installed, the audit plugin enables MySQL Server to produce a log file containing an audit record of server activity. The log contents include when clients connect and disconnect, and what actions they perform while connected, such as which databases and tables they access.

For more information, see MySQL Enterprise Audit.

The internal interface of the Thread Pool plugin has changed. Old versions of the plugin will work with current versions of the server, but versions of the server older than 5.5.28 will not work with current versions of the plugin.

InnoDB: Inserting data of varying record lengths into an InnoDB table that used compression could cause the server to halt with an error. (Bug #14554000, Bug #13523839, Bug #63815, Bug #12845774, Bug #61456, Bug #12595091, Bug #61208)

InnoDB: Under heavy load of concurrent DML and queries, an InnoDB table with a unique index could return nonexistent duplicate rows to a query. (Bug #14399148, Bug #66134)

InnoDB: Deleting from an InnoDB table containing a prefix index, and subsequently dropping the index, could cause a crash with an assertion error. (Bug #13807811)

InnoDB: Certain INFORMATION_SCHEMA tables originally introduced in MySQL 5.6 are now also available in MySQL 5.5 and MySQL 5.1: INNODB_BUFFER_PAGE, INNODB_BUFFER_PAGE_LRU, and INNODB_BUFFER_POOL_STATS. (Bug #13113026)

InnoDB: When a SELECT ... FOR UPDATE, UPDATE, or other SQL statement scanned rows in an InnoDB table using a < or <= operator in a WHERE clause, the next row after the affected range could also be locked. This issue could cause a lock wait timeout for a row that was not expected to be locked. The issue occurred under various isolation levels, such as READ COMMITTED and REPEATABLE READ. (Bug #11765218)

Partitioning: When used with a table having multiple columns in its primary key, but partitioned by KEY using a column that was not part of the primary key as the partitioning column, a query using an aggregate function and DISTINCT such as SELECT SUM(DISTINCT pk_column_1) FROM table WHERE pk_column_2 = constant was not handled correctly. (Bug #14495351)

Partitioning: For tables using PARTITION BY HASH or PARTITION BY KEY, when the partition pruning mechanism encountered a multi-range list or inequality using a column from the partitioning key, it continued with the next partitioning column and tried to use it for pruning, even if the previous column could not be used. This caused partitions which possibly matched one or more of the previous partitioning columns to be pruned away, leaving partitions that matched only the last column of the partitioning key.

This issue was triggered when both of the following conditions were met:

An example of a statement creating a partitioned table and a query against this for which the issue described above occurred is shown here:

CREATE TABLE t1 (
  c1 INT,
  c2 INT,
  PRIMARY KEY(c2, c1)
) PARTITION BY KEY()  # Use primary key as partitioning key
  PARTITIONS 2;

SELECT * FROM t1 WHERE c2 = 2 AND c1 <> 2;

This issue is resolved by ensuring that partition pruning skips any remaining partitioning key columns once a partition key column that cannot be used in pruning is encountered. (Bug #14342883)

Partitioning: The buffer for the row currently read from each partition used for sorted reads was allocated on open and freed only when the partitioning handler was closed or destroyed. For SELECT statements on tables with many partitions and large rows, this could cause the server to use excessive amounts of memory.

This issue has been addressed by allocating buffers for reads from partitioned tables only when they are needed and freeing them immediately once they are no longer needed. As part of this fix, memory is now allocated for reading from rows only in partitions that have not been pruned (see Partition Pruning). (Bug #13025132)

References: See also: Bug #11764622, Bug #14537277.

Replication; Microsoft Windows: On 64-bit Windows platforms, values greater than 4G for the max_binlog_cache_size and max_binlog_stmt_cache_size system variables were truncated to 4G. This caused LOAD DATA INFILE to fail when trying to load a file larger than 4G in size, even when max_binlog_cache_size was set to a value greater than this. (Bug #13961678)

Replication: In master-master replication with --log-slave-updates enabled, setting a user variable and then performing inserts using this variable caused the Exec_master_log_position column in the output of SHOW SLAVE STATUS not to be updated. (Bug #13596613)

When resolving outer fields, Item_field::fix_outer_fields() creates new Item_refs for each execution of a prepared statement, so these must be allocated in the runtime memroot. The memroot switching before resolving JOIN::having caused these to be allocated in the statement root, leaking memory for each prepared statement execution. (Bug #14409015)

The RPM spec file now also runs the test suite on the new binaries, before packaging them. (Bug #14318456)

The argument for LIMIT must be an integer, but if the argument was given by a placeholder in a prepared statement, the server did not reject noninteger values such as '5'. (Bug #13868860)

The Thread Pool plugin did not respect the wait_timeout timeout for client sessions. (Bug #13699303)

CHECK TABLE and REPAIR TABLE could crash if a key definition differed in the .frm and .MYI files of a MyISAM table. Now the server produces an error. (Bug #13555854)

A query for a FEDERATED table could return incorrect results when the underlying table had a compound index on two columns and the query included an AND condition on the columns. (Bug #12876932)

The argument to the --ssl-key option was not verified to exist and be a valid key. The resulting connection used SSL, but the key was not used. (Bug #62743, Bug #13115401)

mysqlhotcopy failed for databases containing views. (Bug #62472, Bug #13006947, Bug #12992993)

Adding a LIMIT clause to a query containing GROUP BY and ORDER BY could cause the optimizer to choose an incorrect index for processing the query, and return more rows than required. (Bug #54599, Bug #11762052)

mysqlbinlog did not accept input on the standard input when the standard input was a pipe. (Bug #49336, Bug #11757312)

Functionality Added or Changed

Bugs Fixed

Important Change: The YEAR(2) data type is now deprecated because it is problematic. Support for YEAR(2) will be removed in a future MySQL release. For more information, see YEAR(2) Limitations and Migrating to YEAR(4).

The mysql_clear_password cleartext client-side authentication plugin is intended for authentication schemes that require the server to receive the password as entered on the client side, without hashing. Because the password is sent in the clear, this plugin should be used within the context of a secure connection, such as an SSL connection, to avoid exposing the password over the network. To make inadvertent use of this plugin less likely, it is now required that clients explicitly enable it. This can be done several ways:

InnoDB: A race condition could cause assertion errors during a DROP TABLE statement for an InnoDB table. Some internal InnoDB functions did not correctly determine if a tablespace was missing; other functions did not handle the error code correctly if a tablespace was missing. (Bug #14251529)

InnoDB: If a row was deleted from an InnoDB table, then another row was re-inserted with the same primary key value, an attempt by a concurrent transaction to lock the row could succeed when it should have waited. This issue occurred if the locking select used a WHERE clause that performed an index scan using a secondary index. (Bug #14100254, Bug #65389)

InnoDB: An assertion could be raised if an InnoDB table was moved to a different database using ALTER TABLE ... RENAME while the database was being dropped by DROP DATABASE. (Bug #13982017)

InnoDB: Using the KILL statement to terminate a query could cause an unnecessary message in the error log:

[ERROR] Got error -1 when reading table table_name

(Bug #13933132)

InnoDB: For an InnoDB table with a trigger, under the setting innodb_autoinc_lock_mode=1, sometimes auto-increment values could be interleaved when inserting into the table from two sessions concurrently. The sequence of auto-increment values could vary depending on timing, leading to data inconsistency in systems using replication. (Bug #12752572, Bug #61579)

Partitioning: Insertion of an out-of-range value into a partitioned table was not handled correctly in all cases. This is a regression that first appeared in MySQL 5.5.23. (Bug #14005441, Bug #65587)

Replication: An event whose length exceeded the size of the master dump thread's max_allowed_packet caused replication to fail. This could occur when updating many large rows and using row-based replication.

As part of this fix, a new server option --slave-max-allowed-packet is added, which permits max_allowed_packet to be exceeded by the slave SQL and I/O threads. Now the size of a packet transmitted from the master to the slave is checked only against this value (available as the value of the slave_max_allowed_packet server system variable), and not against the value of max_allowed_packet. (Bug #12400221, Bug #60926)

Replication: Statements such as UPDATE ... WHERE primary_key_column = constant LIMIT 1 are flagged as unsafe for statement-based logging, despite the fact that such statements are actually safe. In cases where a great many such statements were run, this could lead to disk space becoming exhausted do to the number of such false warnings being logged. To prevent this from happening, a warning suppression mechanism is introduced. This warning suppression acts as follows: Whenever the 50 most recent ER_BINLOG_UNSAFE_STATEMENT warnings have been generated more than 50 times in any 50-second period, warning suppression is enabled. When activated, this causes such warnings not to be written to the error log; instead, for each 50 warnings of this type, a note is written to the error log stating The last warning was repeated N times in last S seconds. This continues as long as the 50 most recent such warnings were issued in 50 seconds or less; once the number of warnings has decreased below this threshold, the warnings are once again logged normally.

The fix for this issue does not affect how these warnings are reported to MySQL clients; a warning is still sent to the client for each statement that generates the warning. This fix also does not make any changes in how the safety of any statement for statement-based logging is determined. (Bug #11759333, Bug #51638)

References: See also: Bug #11751521, Bug #42415.

Replication: After upgrading a replication slave to MySQL 5.5.18 or later, enabling the query cache eventually caused the slave to fail. (Bug #64624, Bug #14005409)

The server did not build with gcc 4.7. (Bug #14238406)

Certain arguments to RPAD() could lead to “uninitialized variable” warnings. (Bug #14039955)

When the index enforcing a foreign key constraint was dropped while foreign_key_checks=0, further operations involving the foreign key column could cause a serious error after the foreign_key_checks option was re-enabled. (Bug #14025221)

COUNT(DISTINCT(SELECT 1)) could be evaluated incorrectly if the optimizer used Loose Index Scan. (Bug #13444084)

References: See also: Bug #13813126.

The presence of a file named .empty in the test database prevented that database from being dropped. (Bug #12845091)

For some subqueries that should be executed using a range scan on a nonprimary index and required use of filesort, only the first execution of the subquery was done as a range scan. All following executions were done as full table scans, resulting in poor performance. (Bug #12667154)

If an account had a nonzero MAX_USER_CONNECTIONS value, that value was not always respected. (Bug #65104, Bug #14003080)

MySQL builds failed with CMake 2.8.8. (Bug #65050, Bug #14017376)

COUNT(DISTINCT(IF ...)) could be evaluated incorrectly if the optimizer used Loose Index Scan. (Bug #64445, Bug #13813126)

References: See also: Bug #13444084.

File access by the ARCHIVE storage engine was not instrumented and thus not shown in Performance Schema tables. (Bug #63340, Bug #13417440)

Sessions could end up deadlocked when executing a combination of SELECT, DROP TABLE, KILL, and SHOW ENGINE INNODB STATUS. (Bug #60682, Bug #12636001)

Using CONCAT() to construct a pattern for a LIKE pattern match could result in memory corrupting and match failure. (Bug #59140, Bug #11766101)

mysqlbinlog exited with no error code if file write errors occurred. (Bug #55289, Bug #11762667)

yaSSL rejected valid SSL certificates that OpenSSL accepts. (Bug #54348, Bug #11761822)

mysqldump could dump views and the tables on which they depend in such an order that errors occurred when the dump file was reloaded. (Bug #44939, Bug #11753490)

A regression bug in the optimizer could cause excessive disk usage for UPDATE statements on InnoDB tables. For tables created with innodb_file_per_table enabled, OPTIMIZE TABLE can be used to recover excessive space used. For tables created in the InnoDB system tablespace,it is necessary to perform a dump and restore into a new instance of the system tablespace. (Bug #65745, Bug #14248833)

Functionality Added or Changed

Bugs Fixed

Important Change; Replication: The SHOW BINARY LOGS statement (and its equivalent SHOW MASTER LOGS) may now be executed by a user with the REPLICATION CLIENT privilege. (Formerly, the SUPER privilege was necessary to use either form of this statement.)

The --safe-mode server option now is deprecated and will be removed in MySQL 5.6.

Performance; InnoDB: Improved the algorithm related to adaptive flushing. This fix increases the rate of flushing in cases where compression is used and the data set is larger than the buffer pool, leading to eviction. (Bug #13990648, Bug #65061)

InnoDB: In a transaction using the REPEATABLE READ isolation level, an UPDATE or DELETE statement for an InnoDB table could sometimes overlook rows recently committed by other transactions. As explained in Consistent Nonlocking Reads, DML statements within a REPEATABLE READ transaction apply to rows committed by other transactions, even if a query could not see those rows. (Bug #14007649, Bug #65111)

InnoDB: The Innodb_buffer_pool_pages_flushed status variable was incorrectly set to twice the value it should be. Its value should never exceed the value of Innodb_pages_written. (Bug #14000361, Bug #65030)

InnoDB: The error handling and message was improved for attempting to create a foreign key with a column referencing itself. The message suggested a potential problem with the data dictionary, when no such problem existed. (Bug #12902967)

InnoDB: The CHECK TABLE statement could fail for a large InnoDB table due to a timeout value of 2 hours. For typical storage devices, the issue could occur for tables that exceeded approximately 200 or 350 GB, depending on I/O speed. The fix relaxes the locking performed on the table being checked, which makes the timeout less likely. It also makes InnoDB recognize the syntax CHECK TABLE QUICK, which avoids the possibility of the timeout entirely. (Bug #11758510, Bug #50723)

Replication: It was theoretically possible for concurrent execution of more than one instance of SHOW BINLOG EVENTS to crash the MySQL Server. (Bug #13979418)

Replication: Statements using AUTO_INCREMENT, LAST_INSERT_ID(), RAND(), or user variables could be applied in the wrong context on the slave when using statement-based replication and replication filtering server options (see How Servers Evaluate Replication Filtering Rules). (Bug #11761686, Bug #54201)

References: See also: Bug #11754117, Bug #45670, Bug #11746146, Bug #23894.

Replication: An INSERT into a table that has a composite primary key that includes an AUTO_INCREMENT column that is not the first column of this composite key is not safe for statement-based binary logging or replication. Such statements are now marked as unsafe and fail with an error when using the STATEMENT binary logging format. For more information, see Determination of Safe and Unsafe Statements in Binary Logging, as well as Replication and AUTO_INCREMENT.

(Bug #11754117, Bug #45670)

References: See also: Bug #11761686, Bug #54201, Bug #11746146, Bug #23894.

For queries with ORDER BY COUNT(*) and LIMIT, the optimizer could choose an execution plan that produced incorrect results. (Bug #12713907)

SHOW TABLES was very slow unless the required information was already in the disk cache. (Bug #60961, Bug #12427262)

When dumping the mysql database, mysqldump did not include the general_log and slow_query_log tables because they cannot be locked. This caused a problem after reloading the dump file if that file contained a DROP DATABASE statement for the mysql database: The database no longer contained the log tables and attempts to log to them failed. Now mysqldump includes statements to re-create the general_log and slow_query_log tables so that they exist after loading the dump file. Log table contents still are not dumped. (Bug #45740, Bug #11754178)

Functionality Added or Changed

Bugs Fixed

Important Change; Replication: INSERT ON DUPLICATE KEY UPDATE is now marked as unsafe for statement-based replication if the target table has more than one primary or unique key. For more information, see Determination of Safe and Unsafe Statements in Binary Logging. (Bug #58637, Bug #11765650, Bug #13038678)

Security Fix: A security bug was fixed. (Bug #64884)

InnoDB; Replication: When binary log statements were replayed on the slave, the Com_insert, Com_update, and Com_delete counters were incremented by BEGIN statements initiating transactions affecting InnoDB tables but not by COMMIT statements ending such transactions. This affected these statements whether they were replicated or they were run using mysqlbinlog. (Bug #12662190)

InnoDB: Running concurrent bulk inserts on a server with auto_increment_offset=1, auto_increment_increment greater than 1, and innodb_autoinc_lock_mode=1 could result in intermittent errors like the following, even with the primary key set to auto_increment and omitted from the INSERT statement:

Duplicate entry 'value' for key 'PRIMARY'

The workaround was to set auto_increment_offset=1 or innodb_autoinc_lock_mode=0 (“traditional”). (Bug #13817703, Bug #61209)

Passing a user variable as an argument to GROUP_CONCAT() could cause a server exit if the variable value changed during query execution. (Bug #12408412)

mysql_store_result() and mysql_use_result() are not for use with prepared statements and are not intended to be called following mysql_stmt_execute(), but failed to return an error when invoked that way in libmysqld. (Bug #62136, Bug #13738989)

References: See also: Bug #47485.

If the --bind-address option was given a host name value and the host name resolved to more than one IP address, the server failed to start. For example, with --bind-address=localhost, if localhost resolved to both 127.0.0.1 and ::1, startup failed. Now the server prefers the IPv4 address in such cases. (Bug #61713, Bug #12762885)

On Windows, mysqlslap crashed for attempts to connect using shared memory. (Bug #31173, Bug #11747181, Bug #59107, Bug #11766072)

Functionality Added or Changed

Bugs Fixed

The MySQL-shared-compat RPM package enables users of Red Hat-provided mysql-*-5.1 RPM packages to migrate to Oracle-provided MySQL-*-5.5 packages. MySQL-shared-compat now replaces the Red Hat mysql-libs package by replacing libmysqlclient.so files of the latter package, thus satisfying dependencies of other packages on mysql-libs. This change affects only users of Red Hat (or Red Hat-compatible) RPM packages. Nothing is different for users of Oracle RPM packages. (Bug #13867506)

Security Fix: A security bug was fixed. (Bug #59533)

Performance; InnoDB; Partitioning: The statistics used by the optimizer for queries against partitioned InnoDB tables were based only on the first partition of each such table, leading to use of the wrong execution plan. (Bug #13694811)

References: This issue is a regression of: Bug #11756867.

Performance; InnoDB: This fix improves the speed of DROP TABLE for InnoDB tables by removing a scan of the buffer pool to remove entries for the adaptive hash index. This improvement is most noticeable on systems with very large buffer pools and the innodb_adaptive_hash_index option enabled. (Bug #13704145, Bug #64284)

Important Change; Partitioning: The query cache did not always function correctly with partitioned tables in a transactional context. For this reason, the query cache is now disabled for any queries using partitioned tables, and such queries can no longer be cached. For more information, see Restrictions and Limitations on Partitioning. (Bug #11761296, Bug #53775)

InnoDB: The performance_schema counters for InnoDB RW-locks did not record some cases where mini-transactions acquired locks. (Bug #13860722)

InnoDB: Deleting a huge amount of data from InnoDB tables within a short time could cause the purge operation that removes delete-marked records to stall. This issue could result in unnecessary disk space use, but does not cause any problems with data integrity. If this issue causes a disk space shortage, restart the server to work around it. This issue is only likely to occur on 32-bit platforms. (Bug #13847885)

InnoDB: Running concurrent bulk inserts on a server with auto_increment_offset=1, auto_increment_increment greater than 1, and innodb_autoinc_lock_mode=1 could result in intermittent errors like the following, even with the primary key set to auto_increment and omitted from the INSERT statement:

Duplicate entry 'value' for key 'PRIMARY'

The workaround was to set auto_increment_offset=1 or innodb_autoinc_lock_mode=0 (“traditional”). (Bug #13817703, Bug #61209)

InnoDB: If the server crashed during a TRUNCATE TABLE or CREATE INDEX statement for an InnoDB table, or a DROP DATABASE statement for a database containing InnoDB tables, an index could be corrupted, causing an error message when accessing the table after restart:

InnoDB: Error: trying to load index index_name for table table_name
InnoDB: but the index tree has been freed!

In MySQL 5.1, this fix applies to the InnoDB Plugin, but not the built-in InnoDB storage engine. (Bug #12861864, Bug #11766019)

InnoDB: When data was removed from an InnoDB table, newly inserted data might not reuse the freed disk blocks, leading to an unexpected size increase for the system tablespace or .ibd file (depending on the setting of innodb_file_per_table. The OPTIMIZE TABLE could compact a .ibd file in some cases but not others. The freed disk blocks would eventually be reused as additional data was inserted. (Bug #11766634, Bug #59783)

InnoDB: When shutting down the MySQL server, the cleanup operations of the InnoDB shutdown could take a long time with no output, making the server appear to be hung.

[Note] mysqld: Normal shutdown
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number ...

Now additional progress messages are displayed between the “starting” and “completed” messages:

InnoDB: Waiting for srv_monitor_thread (srv_lock_timeout_thread/ srv_error_monitor_thread) to exit
InnoDB: Waiting for %lu active transactions to exit
InnoDB: Waiting for master thread (worker threads) to be suspended
InnoDB: Pending checkpoint_writes: %lu
InnoDB: Pending log flush writes: %lu
InnoDB: Waiting for %lu buffer page I/Os to complete
InnoDB: Waiting for dirty buffer pages to be flushed

For both fast shutdown and slow shutdown, a progress messages is printed every 60 seconds:

InnoDB: Waiting for %lu tables to be dropped

During a slow shutdown, two additional messages are printed if certain phases take longer than normal:

InnoDB: Waiting for %lu undo logs to be purged
InnoDB: number of pages just purged: %lu

InnoDB: Waiting for change buffer merge to complete\n
InnoDB: number of bytes of change buffer just merged:  %lu

(Bug #11755873, Bug #47707)

InnoDB: Fast index creation in the InnoDB Plugin could fail, leaving the new secondary index corrupted. (Bug #54330)

Replication: Formerly, the default value shown for the Port column in the output of SHOW SLAVE HOSTS was 3306 whether the port had been set incorrectly or not set at all. Now, when the slave port is not set, the actual port used by the slave is shown. This change also affects the default shown for the --report-port server option. (Bug #13333431)

Replication: The --relay-log-space-limit option was sometimes ignored.

More specifically, when the SQL thread went to sleep, it allowed the I/O thread to queue additional events in such a way that the relay log space limit was bypassed, and the number of events in the queue could grow well past the point where the relay logs needed to be rotated. Now in such cases, the SQL thread checks to see whether the I/O thread should rotate and provide the SQL thread a chance to purge the logs (thus freeing space).

Note that, when the SQL thread is in the middle of a transaction, it cannot purge the logs; it can only ask for more events until the transaction is complete. Once the transaction is finished, the SQL thread can immediately instruct the I/O thread to rotate. (Bug #12400313, Bug #64503)

References: See also: Bug #13806492.

An infinite thread loop could develop within Performance Schema, causing the server to become unresponsive. (Bug #13898343)

Incorrect stored program caching could cause statements within a stored program that included a GROUP BY clause to return different results across multiple program invocations. (Bug #13805127)

Mishandling of NO_BACKSLASH_ESCAPES SQL mode within stored procedures on slave servers could cause replication failures. (Bug #12601974)

SAVEPOINT statements were incorrectly disallowed within XA transactions. (Bug #64374, Bug #13737343)

References: See also: Bug #11766752.

The Performance Schema incorrectly displayed some backslashes in Windows file names (by doubling them). (Bug #63339, Bug #13417446)

On OS X 10.5, the MySQL Preference Pane did not run on Intel-based systems. (Bug #60712, Bug #13788147)

SHOW statements treated stored procedure, stored function, and event names as case sensitive. (Bug #56224, Bug #11763507)

Functionality Added or Changed

Bugs Fixed

InnoDB: A deprecation warning is now issued when --ignore-builtin-innodb is used. (Bug #13586262)

yaSSL was upgraded from version 1.7.2 to 2.2.0. (Bug #13706828)

References: See also: Bug #13713205.

Security Fix: A security bug was fixed. (Bug #63775)

Important Change; InnoDB: When a row grew in size due to an UPDATE operation, other (non-updated) columns could be moved to off-page storage so that information about the row still fit within the constraints of the InnoDB page size. The pointer to the new allocated off-page data was not set up until the pages were allocated and written, potentially leading to lost data if the system crashed while the column was being moved out of the page. The problem was more common with tables using ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED along with the Barracuda file format, particularly with the innodb_file_per_table setting enabled, because page allocation operations are more common as the .ibd tablespace files are extended. Still, the problem could occur with any combination of InnoDB version, file format, and row format.

A related issue was that during such an UPDATE operation, or an INSERT operation that reused a delete-marked record, other transactions could see invalid data for the affected column, regardless of isolation level.

The fix corrects the order of operations for moving the column data off the original page and replacing it with a pointer. Now if a crash occurs at the precise moment when the column data is being transferred, the transfer will not be re-run during crash recovery.

In MySQL 5.1, this fix applies to the InnoDB Plugin, but not the built-in InnoDB storage engine. (Bug #13721257, Bug #12612184, Bug #12704861)

InnoDB: An erroneous assertion could occur, in debug builds only, when creating an index on a column containing zero-length values (that is, ''). (Bug #13654923)

InnoDB: A DDL operation such as ALTER TABLE ... ADD COLUMN could stall, eventually timing out with an Error 1005: Can't create table message referring to fil_rename_tablespace. (Bug #13636122, Bug #62100, Bug #63553)

InnoDB: A DDL operation for an InnoDB table could cause a busy MySQL server to halt with an assertion error:

InnoDB: Failing assertion: trx->error_state == DB_SUCCESS

The error occurred if the DDL operation was run while all 1023 undo slots were in use by concurrent transactions. This error was less likely to occur in MySQL 5.5 and 5.6, because raising the number of InnoDB undo slots increased the number of simultaneous transactions (corresponding to the number of undo slots) from 1K to 128K. (Bug #12739098, Bug #62401)

InnoDB: Server startup could produce an error for temporary tables using the InnoDB storage engine, if the path in the $TMPDIR variable ended with a / character. The error log would look like:

120202 19:21:26  InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: If you are installing InnoDB, remember that you must create
InnoDB: directories yourself, InnoDB does not create them.
120202 19:21:26  InnoDB: Error: trying to open a table, but could not
InnoDB: open the tablespace file './t/#sql7750_1_0.ibd'!
InnoDB: Have you moved InnoDB .ibd files around without using the
InnoDB: commands DISCARD TABLESPACE and IMPORT TABLESPACE?
InnoDB: It is also possible that this is a temporary table #sql...,
InnoDB: and MySQL removed the .ibd file for this.

The workaround for the problem was to create a similar temporary table again, copy its .frm file to tmpdir under the name mentioned in the error message (for example, #sql123.frm) and restart mysqld with tmpdir set to its normal value without a trailing slash, for example /var/tmp. On startup, MySQL would see the .frm file and issue DROP TABLE for the orphaned temporary table. (Bug #11754376, Bug #45976)

Replication: Statements that wrote to tables with AUTO_INCREMENT columns based on an unordered SELECT from another table could lead to the master and the slave going out of sync, as the order in which the rows are retrieved from the table may differ between them. Such statements include any INSERT ... SELECT, REPLACE ... SELECT, or CREATE TABLE ... SELECT statement. Such statements are now marked as unsafe for statement-based replication, which causes the execution of one to throw a warning, and forces the statement to be logged using the row-based format if the logging format is MIXED. (Bug #11758263, Bug #50440)

After using an ALTER TABLE statement to change the KEY_BLOCK_SIZE property for an InnoDB table, for example when switching from an uncompressed to a compressed table, subsequent server restarts could fail with a message like:

InnoDB: Error: data file path/ibdata2 uses page size 1024,
InnoDB: but the only supported page size in this release is=16384

This issue is a regression introduced in MySQL 5.5.20. (Bug #13698765, Bug #64160)

The contents of the shared and shared-compat RPM packages had been changed in versions 5.5.6 and 5.6.1 to avoid the overlap which they traditionally had (and still have in MySQL 5.0 and 5.1). However, the RPM meta information had not been changed in accordance, and so RPM still assumed a conflict between shared and shared-compat RPM packages. This has been fixed. (Bug #60855, Bug #12368215)

References: See also: Bug #56150.

myisam_sort_buffer_size could not be set larger than 4GB on 64-bit systems. (Bug #45702, Bug #11754145)

Due to improper locking, concurrent inserts into an ARCHIVE table at the same time as repair and check operations on the table resulted in table corruption. (Bug #37280, Bug #11748748)

Functionality Added or Changed

Bugs Fixed

A new CMake option, MYSQL_PROJECT_NAME, can be set on Windows or OS X to be used in the project name. (Bug #13551687)

New utf8_general_mysql500_ci and ucs2_general_mysql500_ci collations have been added that preserve the behavior of utf8_general_ci and ucs2_general_ci from versions of MySQL previous to 5.1.24. Bug #27877 corrected an error in the original collations but introduced an incompatibility for columns that contain German 'ß' LATIN SMALL LETTER SHARP S. (As a result of the fix, that character compares equal to characters with which it previously compared different.) A symptom of the problem after upgrading to MySQL 5.1.24 or newer from a version older than 5.1.24 is that CHECK TABLE produces this error:

Table upgrade required.
Please do "REPAIR TABLE `t`" or dump/reload to fix it!

Unfortunately, REPAIR TABLE could not fix the problem. The new collations permit older tables created before MySQL 5.1.24 to be upgraded to current versions of MySQL.

To convert an affected table after a binary upgrade that leaves the table files in place, alter the table to use the new collation. Suppose that the table t1 contains one or more problematic utf8 columns. To convert the table at the table level, use a statement like this:

ALTER TABLE t1
CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_mysql500_ci;

To apply the change on a column-specific basis, use a statement like this (be sure to repeat the column definition as originally specified except for the COLLATE clause):

ALTER TABLE t1
MODIFY c1 CHAR(N) CHARACTER SET utf8 COLLATE utf8_general_mysql500_ci;

To upgrade the table using a dump and reload procedure, dump the table using mysqldump, modify the CREATE TABLE statement in the dump file to use the new collation, and reload the table.

After making the appropriate changes, CHECK TABLE should report no error.

For more information, see Checking Whether Tables or Indexes Must Be Rebuilt, and Rebuilding or Repairing Tables or Indexes. (Bug #43593, Bug #11752408)

References: See also: Bug #27877.

Performance; InnoDB: Memory allocation for InnoDB tables was reorganized to reduce the memory overhead for large numbers of tables or partitions, avoiding situations where the “resident set size” could grow regardless of FLUSH TABLES statements. The problem was most evident for tables with large row size. Some of the memory that was formerly allocated for every open table is now allocated only when the table is modified for the first time. (Bug #11764622, Bug #57480)

Incompatible Change: An earlier change (in MySQL 5.1.59 and 5.5.16) was found to modify date-handling behavior in General Availability-status series (MySQL 5.1 and 5.5). This change has been reverted.

The change was that several functions became more strict when passed a DATE() function value as their argument, thus they rejected incomplete dates with a day part of zero. These functions were affected: CONVERT_TZ(), DATE_ADD(), DATE_SUB(), DAYOFYEAR(), LAST_DAY(), TIMESTAMPDIFF(), TO_DAYS(), TO_SECONDS(), WEEK(), WEEKDAY(), WEEKOFYEAR(), YEARWEEK(). The previous behavior has been restored. (Bug #13458237)

InnoDB: A Valgrind error was fixed in the function os_aio_init(). (Bug #13612811)

InnoDB: The server could crash when creating an InnoDB temporary table under Linux, if the $TMPDIR setting points to a tmpfs filesystem and innodb_use_native_aio is enabled, as it is by default in MySQL 5.5.4 and higher. The entry in the error log looked like:

101123  2:10:59  InnoDB: Operating system error number 22 in a file operation.
InnoDB: Error number 22 means 'Invalid argument'.

The crash occurred because asynchronous I/O is not supported on tmpfs in some Linux kernel versions. The workaround was to turn off the innodb_use_native_aio setting or use a different temporary directory. The fix causes InnoDB to turn off the innodb_use_native_aio setting automatically if it detects that the temporary file directory does not support asynchronous I/O. (Bug #13593888, Bug #11765450, Bug #58421)

InnoDB: References to C preprocessor symbols and macros HAVE_purify, UNIV_INIT_MEM_TO_ZERO, and UNIV_SET_MEM_TO_ZERO were removed from the InnoDB source code. They were only used in debug builds instrumented for Valgrind. They are replaced by calls to the UNIV_MEM_INVALID() macro. (Bug #13418934)

InnoDB: The MySQL server could halt with an assertion error:

InnoDB: Failing assertion: page_get_n_recs(page) > 1

Subsequent restarts could fail with the same error. The error occurred during a purge operation involving the InnoDB change buffer. The workaround was to set the configuration option innodb_change_buffering=inserts. (Bug #13413535, Bug #61104)

InnoDB: With 1024 concurrent InnoDB transactions running concurrently and the innodb_file_per_table setting enabled, a CREATE TABLE operation for an InnoDB table could fail. The .ibd file from the failed CREATE TABLE was left behind, preventing the table from being created later, after the load had dropped.

The fix adds error handling to delete the erroneous .ibd file. This error was less likely to occur in MySQL 5.5 and 5.6, because raising the number of InnoDB undo slots increased the number of simultaneous transactions needed to trigger the bug, from 1K to 128K. (Bug #12400341)

InnoDB: When copying a partitioned InnoDB table from a Linux system to a Windows system, you could encounter this error:

101115 14:19:53 [ERROR] Table .\test\d has no primary key in InnoDB data
dictionary, but has one in MySQL!

Normally, the solution to copy InnoDB tables from Linux to Windows is to create the tables on Linux with the lower_case_table_names option enabled. Partitioned tables, with #P# appended to the filename, were not covered by that solution. (Bug #11765438, Bug #58406)

Replication: Executing mysqlbinlog with the --start-position=N option, where N was equal either to 0 or to a value greater than the length of the dump file, caused it to crash.

This issue was introduced in MySQL 5.5.18 by the fix for Bug #32228 and Bug #11747416. (Bug #13593869, Bug #64035)

References: This issue is a regression of: Bug #32228, Bug #11747416.

Replication: It was possible on replication slaves where FEDERATED tables were in use to get timeouts on long-running operations, such as Error 1160 Got an error writing communication packets. The FEDERATED tables did not need to be replicated for the issue to occur. (Bug #11758931, Bug #51196)

References: See also: Bug #12896628, Bug #61790.

Replication: On Windows replication slave hosts, STOP SLAVE took an excessive length of time to complete when the master was down. (Bug #11752315, Bug #43460)

The shared version of libmysqlclient did not export these functions for linking by client programs: get_tty_password(), handle_options(), my_print_help(). (Bug #13604121)

A query that used an index on a CHAR column referenced in a BETWEEN clause could return invalid results. (Bug #13463488, Bug #63437)

Expressions that compared a BIGINT column with any non-integer constant were performed using integers rather than decimal or float values, with the result that the constant could be truncated. This could lead to any such comparison that used <, >, <=, >=, =, !=/<>, IN, or BETWEEN yielding false positive or negative results. (Bug #13463415, Bug #11758543, Bug #63502, Bug #50756)

When the optimizer performed conversion of DECIMAL values while evaluating range conditions, it could produce incorrect results. (Bug #13453382)

When running mysqldump with both the --single-transaction and --flush-logs options, the flushing of the log performed an implicit COMMIT (see Statements That Cause an Implicit Commit), causing more than one transaction to be used and thus breaking consistency. (Bug #12809202, Bug #61854)

It was possible in the event of successive failures for mysqld_safe to restart quickly enough to consume excessive amounts of CPU. Now, on systems that support the sleep and date system utilities, mysqld_safe checks to see whether it has restarted more than 5 times in the current second, and if so, waits 1 second before attempting another restart. (Bug #11761530, Bug #54035)

When used with the --xml option, mysqldump --routines failed to dump any stored routines, triggers, or events. (Bug #11760384, Bug #52792)

If an attempt to initiate a statement failed, the issue could not be reported to the client because it was not prepared to receive any error messages prior to the execution of any statement. Since the user could not execute any queries, they were simply disconnected without providing a clear error.

After the fix for this issue, the client is prepared for an error as soon as it attempts to initiate a statement, so that the error can be reported prior to disconnecting the user. (Bug #11755281, Bug #47032)

The libmysql.dll library was missing several symbols: my_init, mysql_client_find_plugin, mysql_client_register_plugin, mysql_load_plugin, mysql_load_plugin_v, mysql_options4, and mysql_plugin_options. (Bug #69204, Bug #16797982, Bug #62394)

Using myisamchk with the sort recover method to repair a table having fixed-width row format could cause the row pointer size to be reduced, effectively resulting in a smaller maximum data file size. (Bug #48848, Bug #11756869)

On Windows, the server incorrectly constructed the full path name of the plugin binary for INSTALL PLUGIN and CREATE FUNCTION ... SONAME. (Bug #45549, Bug #11754014)

The stored routine cache was subject to a small memory leak that over time or with many routines being used could result in out-of-memory errors.

The fix for this issue also introduces a new global server system variable stored_program_cache which can be used for controlling the size of the stored routine cache. (Bug #44585, Bug #11753187)

Under some circumstances, the result of SUBSTRING_INDEX() incorrectly depended on the contents of the previous row. (Bug #42404, Bug #11751514)

Functionality Added or Changed

Bugs Fixed

A new server option, --slow-start-timeout, controls the Windows service control manager's service start timeout. The value is the maximum number of milliseconds that the service control manager waits before trying to kill the MySQL service during startup. The default value is 15000 (15 seconds). If the MySQL service takes too long to start, you may need to increase this value. A value of 0 means there is no timeout. (Bug #45546, Bug #11754011)

Performance; InnoDB: This fix improved the efficiency and concurrency of freeing pages in the InnoDB buffer pool when performing a DROP TABLE for an InnoDB table when the innodb_file_per_table option is enabled.

This change is most noticeable for systems with large buffer pools. During the drop operation, one traversal of the buffer pool memory structure is changed from the LRU list (the entire buffer pool) to the flush list (a much smaller structure). The LRU scanning is reduced, but not entirely eliminated. The buffer pool mutex is also released periodically, so that if the drop operation takes significant time, other threads can proceed concurrently. (Bug #11759044, Bug #51325)

Important Change; Replication: Setting an empty user in a CHANGE MASTER TO statement caused an invalid internal result and is no longer permitted. Trying to use MASTER_USER='' or setting MASTER_PASSWORD while leaving MASTER_USER unset causes the statement to fail with an error. (Bug #13427949)

Important Change; Replication: Moving the binary log file, relay log file, or both files to a new location, then restarting the server with a new value for --log-bin, --relay-log, or both, caused the server to abort on start. This was because the entries in the index file overrode the new location. In addition, paths were calculated relative to datadir (rather than to the --log-bin or --relay-log values).

The fix for this problem means that, when the server reads an entry from the index file, it now checks whether the entry contains a relative path. If it does, the relative part of the path is replaced with the absolute path set using the --log-bin or --relay-log option. An absolute path remains unchanged; in such a case, the index must be edited manually to enable the new path or paths to be used. (Bug #11745230, Bug #12133)

InnoDB: When doing a live downgrade from MySQL 5.6.4 or later, with innodb_page_size set to a value other than 16384, now the earlier MySQL version reports that the page size is incompatible with the older version, rather than crashing or displaying a “corruption” error. (Bug #13116225)

InnoDB: Certain CREATE TABLE statements could fail for InnoDB child tables containing foreign key definitions. This problem affected Windows systems only, with the setting lower_case_table_names=0. It was a regression from MySQL bug #55222. (Bug #13083023, Bug #60229)

InnoDB: Issuing INSERT...ON DUPLICATE KEY statements for InnoDB tables from concurrent threads could cause a deadlock, particularly with the INSERT...ON DUPLICATE KEY UPDATE form. The problem could also be triggered by issuing multiple INSERT IGNORE statements. The fix avoids deadlocks caused by the same row being accessed by more than one transaction. Deadlocks could still occur when multiple rows are inserted and updated simultaneously by different transactions in inconsistent order; those types of deadlocks require the standard error handling on the application side, of re-trying the transaction. (Bug #11759688, Bug #52020, Bug #12842206)

An incorrect InnoDB assertion could cause the server to halt. This issue only affected debug builds. The assertion referenced the source file btr0pcur.ic and the variable cursor->pos_state. (Bug #13358468)

LOAD INDEX INTO CACHE could cause a server exit if the index cache was too small. (Bug #12361113)

Locale information for FORMAT() function instances was lost in view definitions. (Bug #63020, Bug #13344643)

The handle_segfault() signal-handler code in mysqld could itself crash due to calling unsafe functions. (Bug #54082, Bug #11761576)

Enabling myisam_use_mmap could cause the server to crash. (Bug #48726, Bug #11756764)

Concurrent access to ARCHIVE tables could cause corruption. (Bug #42784, Bug #11751793)

Functionality Added or Changed

Bugs Fixed

Replication: Previously, replication slaves could connect to the master server through master accounts that use nonnative authentication, except Windows native authentication. This is now also true for Windows native authentication.

Performance of metadata locking operations on Windows XP systems was improved by instituting a cache for metadata lock objects. This permits the server to avoid expensive operations for creation and destruction of synchronization objects on XP. A new system variable, metadata_locks_cache_size, permits control over the size of the cache. The default size is 1024. (Bug #12695572)

Important Change; InnoDB: If an ALTER TABLE statement failed for an InnoDB table due to an error code from an underlying file-renaming system call, InnoDB could lose track of the .ibd file for the table. This issue only occurred when the innodb_file_per_table configuration option was enabled, and when the low-level error persisted through thousands of retry attempts. In MySQL 5.1, this issue applied to the InnoDB Plugin but not the built-in InnoDB storage engine.

For example, if you encounter an error like the following:

mysql> alter table sb2 add column d2 int;
ERROR 1025 (HY000): Error on rename of './sbtest/#sql-1eb9_1' to
'./sbtest/sb2' (errno: -1)

you might be able to access the #sql* table by copying a .frm file from a table with an identical schema. The table name to use for the .frm filewould be `sbtest.#mysql50##sql-1eb9_1` in the preceding example. (Bug #12884631, Bug #62146)

InnoDB: An internal deadlock could occur within InnoDB, on a server doing a substantial amount of change buffering for DML operations, particularly DELETE statements. (Bug #13340047)

Replication: When a statement containing a large number of rows to be applied on a slave table that does not contain a primary key, a considerable amount of time can be needed to find and change all the rows that are to be changed. The current fix helps diagnose this issue by printing a message to the error log if the execution time for a given statement replicated using row-based replication takes more than 60 seconds. log_warnings must be greater than 1 for this message to be printed to the error log. (Bug #11760927, Bug #53375)

Rounding DBL_MAX returned DBL_MAX, not 'inf'. (Bug #13261955)

Writes to MyISAM temporary tables could include uninitialized data, which could contain sensitive information. Now only bytes containing initialized data are copied, which also improves performance. (Bug #12997905)

mysql_upgrade did not upgrade the system tables or create the mysql_upgrade_info file when run with the --write-binlog or --skip-write-binlog option. (Bug #60223, Bug #11827359)

If a plugin was uninstalled, thread local variables for plugin variables of string type with wth PLUGIN_VAR_MEMALLOC flag were not freed. (Bug #56652, Bug #11763882)

Deadlock could occur when these four things happened at the same time: 1) An old dump thread was waiting for the binary log to grow. 2) The slave server that replicates from the old dump thread tried to reconnect. During reconnection, the new dump thread tried to kill the old dump thread. 3) A KILL statement tried to kill the old dump thread. 4) An INSERT statement caused a binary log rotation. (Bug #56299, Bug #11763573)

Functionality Added or Changed

Bugs Fixed

Upgrading from an Advanced GPL RPM package to an Advanced RPM package did not work. Now on Linux it is possible to use rpm -U to replace any installed MySQL product by any other of the same release family. It is not necessary to remove the old produce with rpm -e first. (Bug #11886309)

Performance; InnoDB: The process of deallocating the InnoDB Adaptive Hash Index was made faster, during shutdown or when turning off the AHI with the statement:

SET GLOBAL innodb_adaptive_hash_index=OFF;

(Bug #13006367, Bug #62487)

Incompatible Change; Replication: The statements in the following list are now marked as unsafe for statement-based replication. This is due to the fact that each of these statements depends on the results of a SELECT statement whose order cannot always be determined. When using STATEMENT logging mode, a warning is issued in the binary log for any of these statements; when using MIXED logging mode, the statement is logged using the row-based format.

When upgrading, you should note the use of these statements in your applications, keeping in mind that a statement that inserts or replaces rows obtained from a SELECT can take up many times as much space in the binary log when logged using row-based format than when only the statement itself is logged. Depending on the number and size of the rows selected and inserted (or replaced) by any such statements, the difference in size of the binary log after the logging of these statements is switched from statement-based to row-based can potentially be several orders of magnitude. See Advantages and Disadvantages of Statement-Based and Row-Based Replication. (Bug #11758262, Bug #50439)

InnoDB: Fixed a compilation problem that affected the InnoDB source code with gcc 4.6.1. The affected InnoDB source file was btr/btr0cur.c. (Bug #13116045)

InnoDB: An UPDATE statement for an InnoDB table could hang. The issue affects tables using the Barracuda file format and having multiple indexes on column prefixes. The size of an undo log record could exceed the page size, even though the total size of the column prefixes was less than the page size (usually 16KB). In MySQL 5.5 and higher, this error is now reported using the new code ER_UNDO_RECORD_TOO_BIG. In MySQL 5.1 with the InnoDB Plugin, this error is reported using the existing code ER_TOO_BIG_ROWSIZE. (Bug #12547647)

Replication: A replication master could send damaged events to slaves after the binary log disk on the master became full. To correct this issue, only complete events are now pushed by the master dump thread to the slave I/O thread. In addition, the error text that the master sends to the slave when an incomplete event is found now states that the incomplete event may have been caused by running out of disk space on the master, and provides coordinates of the first and the last event bytes read. (Bug #11747416, Bug #32228)

References: See also: Bug #64035, Bug #13593869.

During the table-opening process, memory was allocated and later freed that was needed view loading, even for statements that did not use views. These unnecessary allocation and free operations are no longer done. (Bug #13116518)

mysql_plugin mishandled the --plugin-ini, --mysqld, and --my-print-defaults options under some circumstances. (Bug #12968815)

mysql_plugin returned the wrong error code from failed server bootstrap execution. (Bug #12968567)

Several improvements were made to the libedit library bundled with MySQL distributions, and that is available for all platforms that MySQL supports except Windows.

(Bug #12605400, Bug #12613725, Bug #12618092, Bug #12624155, Bug #12617651, Bug #12605388)

decimal_round() could cause a server exit when processing long numeric strings. (Bug #12563865)

ARCHIVE tables with NULL columns could cause server crashes or become corrupt under concurrent load. (Bug #51252, Bug #11758979)

OPTIMIZE TABLE could corrupt MyISAM tables if myisam_use_mmap was enabled. (Bug #49030, Bug #11757032)

A query that selected a GROUP_CONCAT() function result could return different values depending on whether an ORDER BY of the function result was present. (Bug #41090, Bug #11750518)

For FEDERATED tables, loss of connection to the remote table during some insert operations could cause a server crash. (Bug #34660, Bug #11747970)

Functionality Added or Changed

Bugs Fixed

Replication: Previously, replication slaves could connect to the master server only through master accounts that use native authentication. Now replication slaves can also connect through master accounts that use nonnative authentication (except Windows native authentication) if the required client-side plugin is installed on the slave side in the directory named by the slave plugin_dir system variable. The exception for Windows is lifted in MySQL 5.5.19. (Bug #12897501)

The make_win_bin_dist script is no longer used and has been removed from MySQL distributions and the manual. (Bug #58241)

MEMORY table creation time is now available in the CREATE_TIME column of the INFORMATION_SCHEMA.TABLES table and the Create_time column of SHOW TABLE STATUS output. (Bug #51655, Bug #11759349)

Performance; InnoDB: This fix improves the performance of instrumentation code for InnoDB buffer pool operations. (Bug #12950803, Bug #62294)

InnoDB: Lookups using secondary indexes could give incorrect matches under a specific set of conditions. The conditions involve an index defined on a column prefix, for a BLOB or other long column stored outside the index page, with a table using the Barracuda file format. (Bug #12601439, Bug #12543666)

InnoDB: This fix corrects cases where the MySQL server could hang or abort with a long semaphore wait message. (This is a different issue than when these symptoms occurred during a CHECK TABLE statement.) (Bug #11766591, Bug #59733)

Internal conversion of zero to binary and back could yield a result with incorrect precision. (Bug #12911710)

Valgrind warnings generated by filesort operations were fixed. (Bug #12856915)

mysqld_safe did not properly check for an already running instance of mysqld. (Bug #11878394)

With Valgrind enabled, InnoDB semaphore wait timeouts were too low and could expire. (Bug #11765460)

The help message for mysql_install_db did not indicate that it supports the --defaults-file, --defaults-extra-file and --no-defaults options. (Bug #58898, Bug #11765888)

An assertion designed to detect zero-length sort keys also was raised when the entire key set fit in memory. (Bug #58200, Bug #11765254)

myisampack could create corrupt FULLTEXT indexes when compressing tables. (Bug #53646, Bug #11761180)

A linking problem prevented the FEDERATED storage engine plugin from loading. (Bug #40942, Bug #11750417)

External Authentication

Thread Pool Notes

Functionality Added or Changed

Bugs Fixed

Commercial distributions of MySQL now include two plugins that enable MySQL Server to use external authentication methods to authenticate MySQL users:

These authentication plugins enable MySQL Server to accept connections from users defined outside the MySQL grant tables. They also support the MySQL proxy-user capability. Each plugin can return to MySQL a user name different from the login user, which means that the plugin can return the MySQL user that defines the privileges the externally authenticated user should have. For example, an external user named joe can connect and have the privileges of the MySQL user named developer.

The server-side PAM and Windows authentication plugins are included only in commercial distributions. They are not included in MySQL community distributions. The client-side plugins with which they communicate are included in all distributions, including community distributions. This permits clients from any release to connect to a server that has the server-side plugin loaded.

For more information about these plugins, see The PAM Authentication Plugin, and The Windows Native Authentication Plugin. For general information about pluggable authentication in MySQL, see Pluggable Authentication. For proxy user information, see Proxy Users.

The default thread-handling model in MySQL Server executes statements using one thread per client connection. As more clients connect to the server and execute statements, overall performance degrades. Commercial distributions of MySQL now include a thread pool plugin that provides an alternative thread-handling model designed to reduce overhead and improve performance. The plugin implements a thread pool that increases server performance by efficiently managing statement execution threads for large numbers of client connections.

The thread pool addresses several problems of the one thread per connection model:

On Windows, the thread pool plugin requires Windows Vista or newer. On Linux, the plugin requires kernel 2.6.9 or newer.

For more information, see MySQL Enterprise Thread Pool.

Important Change; Replication: The RESET SLAVE statement has been extended with an ALL keyword. In addition to deleting the master.info, relay-log.info, and all relay log files, RESET SLAVE ALL also clears all connection information otherwise held in memory following execution of RESET SLAVE. (Bug #11809016, Bug #11763210)

The thread pool plugin should be loaded at server startup, and not loaded or unloaded at runtime. An error now occurs for attempts to load or unload it with the INSTALL PLUGIN or UNINSTALL PLUGIN statement.

Some plugins operate in such a matter that they should be loaded at server startup, and not loaded or unloaded at runtime. The plugin API now supports marking plugins this way. The st_mysql_plugin structure now has a flags member, which can be set to the OR of the applicable flags. The PLUGIN_OPT_NO_INSTALL flag indicates that the plugin cannot be loaded at runtime with the INSTALL PLUGIN statement. This is appropriate for plugins that must be loaded at server startup with the --plugin-load option. The PLUGIN_OPT_NO_UNINSTALL flag indicates that the plugin cannot be unloaded at runtime with the UNINSTALL PLUGIN statement.

The new member changes the interface, so the plugin interface version, MYSQL_PLUGIN_INTERFACE_VERSION, has been incremented from 0x0102 to 0x0103. Plugins that require access to the new member must be recompiled to use version 0x0103 or higher.

A new utility, mysql_plugin, enables MySQL administrators to manage which plugins a MySQL server loads. It provides an alternative to manually specifying the --plugin-load option at server startup or using the INSTALL PLUGIN and UNINSTALL PLUGIN statements at runtime. See mysql_plugin — Configure MySQL Server Plugins.

Performance; InnoDB: This fix improves the performance of operations on VARCHAR(N) columns in InnoDB tables, where N is declared as a large value but the actual string values in the table are short. (Bug #12835650)

Performance; InnoDB: The “random read-ahead” feature that was removed from the InnoDB Plugin is now available again. Because it is only helpful for certain workloads, it is turned off by default. To turn it on, enable the innodb_random_read_ahead configuration option. Because this feature can improve performance in some cases and reduce performance in others, before relying on this setting, benchmark both with and without the setting enabled. (Bug #12356373)

Incompatible Change: The mysql_affected_rows() C API function returned 3 (instead of 2) for INSERT ... ON DUPLICATE KEY UPDATE statements where there was a duplicated key value.

Now the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current values. If you specify the CLIENT_FOUND_ROWS flag to mysql_real_connect() when connecting to mysqld, the affected-rows value is 1 (not 0) if an existing row is set to its current values. (Bug #46675, Bug #11754979)

Incompatible Change: Handling of a date-related assertion was modified.

However, a consequence of this change is that several functions become more strict when passed a DATE() function value as their argument and reject incomplete dates with a day part of zero. These functions are affected: CONVERT_TZ(), DATE_ADD(), DATE_SUB(), DAYOFYEAR(), LAST_DAY(), TIMESTAMPDIFF(), TO_DAYS(), TO_SECONDS(), WEEK(), WEEKDAY(), WEEKOFYEAR(), YEARWEEK(). Because this changes date-handling behavior in General Availability-status series (MySQL 5.1 and 5.5), it was reverted in 5.1.62 and 5.5.21. The change is retained in MySQL 5.6.

References: See also: Bug #13458237.

InnoDB: The DATA_LENGTH column in the INFORMATION_SCHEMA.TABLES table now correctly reports the on-disk sizes of tablespaces for InnoDB compressed tables. (Bug #12770537)

InnoDB: With the configuration settings innodb_file_per_table=1 and innodb_file_format=Barracuda, inserting a column value greater than half the page size, and including that column in a secondary index, could cause a crash when that column value was updated. (Bug #12637786)

InnoDB: Unused functions were removed from the internal InnoDB code related to mini-transactions, to clarify the logic. (Bug #12626794, Bug #61240)

Replication: Processing of corrupted table map events could cause the server to crash. This was especially likely if the events mapped different tables to the same identifier, such as could happen due to Bug #56226.

Now, before applying a table map event, the server checks whether the table has already been mapped with different settings, and if so, an error is raised and the slave SQL thread stops. If it has been mapped with the same settings, or if the table is set to be ignored by filtering rules, there is no change in behavior: the event is skipped and IDs are not checked. (Bug #44360, Bug #11753004)

References: See also: Bug #56226, Bug #11763509.

The metadata locking subsystem added too much overhead for INFORMATION_SCHEMA queries that were processed by opening only .frm or .TRG files and had to scan many tables. For example, SELECT COUNT(*) FROM INFORMATION_SCHEMA.TRIGGERS was affected. (Bug #12828477)

Compilation failed on OS X 10.7 (Lion) with a warning: Implicit declaration of function 'pthread_init' (Bug #12779790)

With profiling disabled or not compiled in, set_thd_proc_info() unnecessarily checked file name lengths. (Bug #12756017)

References: This issue is a regression of: Bug #59273.

A DBUG_ASSERT added by Bug #11792200 was overly aggressive in raising assertions. (Bug #12537160)

References: See also: Bug #11792200.

CHECK TABLE and REPAIR TABLE failed to find problems with MERGE tables that had underlying tables missing or with the wrong storage engine. Issues were reported only for the first underlying table. (Bug #11754210)

(5 DIV 2) and (5.0 DIV 2) produced different results (2 versus 3) because the result of the latter expression was not truncated before conversion to integer. This differed from the behavior in MySQL 5.0 and 5.1. Now both expressions produce 2. (Bug #61676, Bug #12711164)

For a lower_case_table_names value of 1 or 2 and a database having a mixed-case name, calling a stored function using a fully qualified name including the database name failed. (Bug #60347, Bug #11840395)

SELECT DISTINCT with a deterministic stored function in the WHERE clause could produce incorrect results. (Bug #59736, Bug #11766594)

The embedded server crashed when argc = 0. (Bug #57931, Bug #12561297)

CREATE TABLE without an ENGINE option determined the default engine at parse rather than execution time. This led to incorrect results if the statement was executed within a stored program and the default engine had been changed in the meantime. (Bug #50614, Bug #11758414)

Upgrades using an RPM package recreated the test database, which is undesirable when the DBA had removed it. (Bug #45415, Bug #11753896)

Functionality Added or Changed

Bugs Fixed

The undocumented --all option for perror is deprecated and will be removed in MySQL 5.6.

Performance; InnoDB: The DROP TABLE command for an InnoDB table could be very slow, in a configuration with a combination of table compression, partitioning, and a large buffer pool. (Bug #12635227, Bug #61188)

InnoDB: A failed CREATE INDEX operation for an InnoDB table could result in some memory being allocated but not freed. This memory leak could affect tables created with the ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED setting. (Bug #12699505)

Partitioning: Auto-increment columns of partitioned tables were checked even when they were not being written to. In debug builds, this could lead to a server crash. (Bug #11765667, Bug #58655)

Partitioning: The UNIX_TIMESTAMP() function was not treated as a monotonic function for purposes of partition pruning. (Bug #11746819, Bug #28928)

Replication: If a LOAD DATA INFILE statement—replicated using statement-based replication—featured a SET clause, the name-value pairs were regenerated using a method (Item::print()) intended primarily for generating output for statements such as EXPLAIN EXTENDED, and which cannot be relied on to return valid SQL. This could in certain cases lead to a crash on the slave.

To fix this problem, the server now names each value in its original, user-supplied form, and uses that to create LOAD DATA INFILE statements for statement-based replication. (Bug #60580, Bug #11902767)

References: See also: Bug #34283, Bug #11752526, Bug #43746.

Compiling the server with maintainer mode enabled failed for gcc 4.6 or higher. (Bug #12727287)

The option-parsing code for empty strings leaked memory. (Bug #12589928)

mysql_list_fields() returned incorrect character set information for character columns of views. (Bug #12337762)

Previously, an inappropriate error message was produced if a multiple-table update for an InnoDB table with a clustered primary key would update a table through multiple aliases, and perform an update that may physically move the row in at least one of these aliases. Now the error message is: Primary key/partition key update is not permitted since the table is updated both as 'tbl_name1' and 'tbl_name2' (Bug #11882110)

References: See also: Bug #11764529.

ALTER TABLE {MODIFY|CHANGE} ... FIRST did nothing except rename columns if the old and new versions of the table had exactly the same structure with respect to column data types. As a result, the mapping of column name to column data was incorrect. The same thing happened for ALTER TABLE DROP COLUMN ... ADD COLUMN statements intended to produce a new version of the table with exactly the same structure as the old version. (Bug #61493, Bug #12652385)

Incorrect handling of metadata locking for FLUSH TABLES WITH READ LOCK for statements requiring prelocking caused two problems:

(Bug #61401, Bug #12641342)

The fractional part of the “Queries per second” value could be displayed incorrectly in MySQL status output (for example, in the output from mysqladmin status or the mysql STATUS command). (Bug #61205, Bug #12565712)

LOAD DATA INFILE incorrectly parsed relative data file path names that ascended more than three levels in the file system and as a consequence was unable to find the file. (Bug #60987, Bug #12403662)

For unknown users, the native password plugin reported incorrectly that no password had been specified even when it had. (Bug #59792, Bug #11766641)

For MyISAM tables, attempts to insert incorrect data into an indexed GEOMETRY column could result in table corruption. (Bug #57323, Bug #11764487)

In debug builds, Field_new_decimal::store_value() was subject to buffer overflows. (Bug #55436, Bug #11762799)

A race condition between loading a stored routine using the name qualified by the database name and dropping that database resulted in a spurious error message: The table mysql.proc is missing, corrupt, or contains bad data (Bug #47870, Bug #11756013)

Functionality Added or Changed

Bugs Fixed

Incompatible Change: In the audit plugin interface, the event_class member was removed from the mysql_event_general structure and the calling sequence for the notification function was changed. Originally, the second argument was a pointer to the event structure. The function now receives this information as two arguments: an event class number and a pointer to the event. Corresponding to these changes, MYSQL_AUDIT_INTERFACE_VERSION was increased to 0x0300.

The plugin_audit.h header file, and the NULL_AUDIT example plugin in the plugin/audit_null directory were modified per these changes. See Writing Audit Plugins.

InnoDB: InnoDB now permits concurrent reads while creating a secondary index. (Bug #11853126)

References: See also: Bug #11751388, Bug #11784056, Bug #11815600.

CMake configuration support on Linux now provides a boolean ENABLE_GCOV option to control whether to include support for gcov. (Bug #12549572)

Client programs now display more information for SSL errors to aid in diagnosis and debugging of connection problems. (Bug #21287, Bug #11745920)

Replication: A mistake in thread cleanup could cause a replication master to crash. (Bug #12578441)

Replication: When using row-based replication and attribute promotion or demotion (see Replication of Columns Having Different Data Types), memory allocated internally for conversion of BLOB columns was not freed afterwards. (Bug #12558519)

Adding support for Windows authentication to libmysqlclient introduced a link dependency on the system Secur32 library. The Microsoft Visual C++ link information now pulls in this library automatically. (Bug #12612143)

Subsequent to Prepared statement needs to be re-prepared errors, inserts into DECIMAL columns caused a server exit. (Bug #12608543)

In some cases, memory allocated for Query_tables_list::sroutines() was not freed properly. (Bug #12429877)

After the fix for Bug #11889186, MAKEDATE() arguments with a year part greater than 9999 raised an assertion. (Bug #12403504)

References: This issue is a regression of: Bug #11889186.

An assertion could be raised due to a missing NULL value check in Item_func_round::fix_length_and_dec(). (Bug #12392636)

An assertion could be raised during two-phase commits if the binary log was used as the transaction coordinator log. (Bug #12346411)

Field_geom::reset() failed to reset its base Field_blob. The range optimizer used the uninitialized field during optimization and execution, causing the server to exit. (Bug #11908153)

A problem introduced in MySQL 5.5.11 caused very old (MySQL 4.0) clients to be unable to connect to the server. (Bug #61222, Bug #12563279)

Using CREATE EVENT IF NOT EXISTS for an event that already existed and was enabled caused multiple instances of the event to run. (Bug #61005, Bug #12546938)

An embedded client aborted rather than issuing an error message if it issued a TEE command (\T file_name) and the directory containing the file did not exist. This occurred because the wrong error handler was called. (Bug #57491, Bug #11764633)

ALTER EVENT could change the event status. (Bug #57156, Bug #11764334)

On some platforms, the Incorrect value: xxx for column yyy at row zzz error produced by LOAD DATA INFILE could have an incorrect value of zzz. (Bug #46895, Bug #11755168)

An attempt to install nonexistent files during installation was corrected. (Bug #43247, Bug #11752142)

On FreeBSD 64-bit builds of the embedded server, exceptions were not prevented from propagating into the embedded application. (Bug #38965, Bug #11749418)

Functionality Added or Changed

Bugs Fixed

The client-side plugin that accompanies the server-side Windows authentication plugin is now included in all MySQL distributions. This will permit clients from any release, whether commercial or community, to connect to a server that has the server-side plugin loaded. See The Windows Native Authentication Plugin (Bug #59780, Bug #11766631)

InnoDB: If the server crashed while an XA transaction was prepared but not yet committed, the transaction could remain in the system after restart, and cause a subsequent shutdown to hang. (Bug #11766513, Bug #59641)

InnoDB: The MySQL server could hang during CREATE TABLE, OPTIMIZE TABLE, or ALTER TABLE or other DDL operation that performs a table copy for an InnoDB table, if such operations were performed by multiple sessions simultaneously. The error was reported as:

InnoDB: Error: semaphore wait has lasted > 600 seconds

(Bug #11760042, Bug #52409)

InnoDB: With the setting lower_case_table_names=2, inserts into InnoDB tables covered by foreign key constraints could fail after a server restart. This is a similar problem to the foreign key error in Bug #11831040 / Bug #60196 / Bug #60909, but with a different root cause and occurring on OS X.

Partitioning: The internal get_partition_set() function did not take into account the possibility that a key specification could be NULL in some cases. (Bug #12380149)

Partitioning: When executing a row-ordered retrieval index merge, the partitioning handler used memory from that allocated for the table, rather than that allocated to the query, causing table object memory not to be freed until the table was closed. (Bug #11766249, Bug #59316)

Replication: When mysqlbinlog was invoked using --base64-output=decode-row and --start-position=pos, (where pos is a point in the binary log past the format description log event), a spurious error of the type shown here was generated:

malformed binlog: it does not contain any Format_description_log_event...

However, since there is nothing unsafe about not printing the format description log event, the error has been removed for this case. (Bug #12354268)

Replication: Typographical errors appeared in the text of several replication error messages. (The word “position” was misspelled as “postion”.) (Bug #11762616, Bug #55229)

Assignments to NEW.var_name within triggers, where var_name had a BLOB or TEXT type, were not properly handled and produced incorrect results. (Bug #12362125)

XA COMMIT could fail to clean up the error state if it discovered that the current XA transaction had to be rolled back. Consequently, the next XA transaction could raise an assertion when it checked for proper cleanup of the previous transaction. (Bug #12352846)

An internal client macro reference was removed from the client_plugin.h header file. This reference made the file unusable. (Bug #60746, Bug #12325444)

For repeated invocation of some stored procedures, the server consumed memory that it did not release until the connection terminated. (Bug #60025, Bug #11848763)

The server did not check for certain invalid out of order sequences of XA statements, and these sequences raised an assertion. (Bug #59936, Bug #11766752, Bug #12348348)

With the conversion from GNU autotools to CMake for configuring MySQL, the USE_SYMDIR preprocessor symbol was omitted. This caused failure of symbolic links (described at Using Symbolic Links). (Bug #59408, Bug #11766320)

An incorrect max_length value for YEAR values could be used in temporary result tables for UNION, leading to incorrect results. (Bug #59343, Bug #11766270)

In Item_func_in::fix_length_and_dec(), a Valgrind warning for uninitialized values was corrected. (Bug #59270, Bug #11766212)

In ROUND() calculations, a Valgrind warning for uninitialized memory was corrected. (Bug #58937, Bug #11765923)

References: This issue is a regression of: Bug #33143.

Valgrind warnings caused by comparing index values to an uninitialized field were corrected. (Bug #58705, Bug #11765713)

LOAD DATA INFILE errors could leak I/O cache memory. (Bug #58072, Bug #11765141)

For LOAD DATA INFILE, multibyte character sequences could be pushed onto a stack too small to accommodate them. (Bug #58069, Bug #11765139)

Internal Performance Schema header files were unnecessarily installed publicly. (Bug #53281)

On Linux, the mysql client built using the bundled libedit did not read ~/.editrc. (Bug #49967, Bug #11757855)

The optimizer sometimes incorrectly processed HAVING clauses for queries that did not also have an ORDER BY clause. (Bug #48916, Bug #11756928)

PROCEDURE ANALYSE() could leak memory for NULL results, and could return incorrect results if used with a LIMIT clause. (Bug #48137, Bug #11756242)

With DISTINCT, CONCAT(col_name,...) returned incorrect results when the arguments to CONCAT() were columns with an integer data type declared with a display width narrower than the values in the column. (For example, if an INT(1) column contained 1111.) (Bug #4082)

Functionality Added or Changed

Bugs Fixed

When invoked with the --auto-generate-sql option, mysqlslap dropped the schema specified with the --create-schema option at the end of the test run, which may have been unexpected by the user. mysqlslap now has a --no-drop option that prevents any schema created during the test run from being dropped. (Bug #58090, Bug #11765157)

InnoDB; Replication: Trying to update a column, previously set to NULL, of an InnoDB table with no primary key caused replication to fail on the slave with Can't find record in 'table'.

(Bug #11766865, Bug #60091)

References: See also: Bug #16566658.

InnoDB: The server could halt if InnoDB interpreted a very heavy I/O load for 15 minutes or more as an indication that the server was hung. This change fixes the logic that measures how long InnoDB threads were waiting, which formerly could produce false positives. (Bug #11877216, Bug #11755413, Bug #47183)

InnoDB: With the setting lower_case_table_names=2, inserts into InnoDB tables covered by foreign key constraints could fail after a server restart. (Bug #11831040, Bug #60196, Bug #60909)

Replication: Using the --server-id option with mysqlbinlog could cause format description log events to be filtered from the binary log, leaving mysqlbinlog unable to read the remainder of the log. Now such events are always read without regard to the value of this option.

As part of the fix for this problem, mysqlbinlog now also reads rotate log events without regard to the value of --server-id. (Bug #59530, Bug #11766427)

On Windows, the server rejected client connections if no DNS server was available. (Bug #12325375)

mysql_upgrade did not properly upgrade the authentication_string column of the mysql.user table. (Bug #11936829)

InnoDB invoked some zlib functions without proper initialization. (Bug #11849231)

CREATE TABLE permitted a TABLESPACE table option but did not write the option value to the .frm file. (Bug #11769356)

Comparison of a DATETIME stored program variable and NOW() resulted in “Illegal mix of collations error” when character_set_connection was set to utf8. (Bug #60625, Bug #11926811)

Selecting from a view for which the definition included a HAVING clause failed with an error:

1356: View '...' references invalid table(s) or column(s)
or function(s) or definer/invoker of view lack rights to use them

(Bug #60295, Bug #11829681)

CREATE TABLE syntax permits specification of a STORAGE {DEFAULT|DISK|MEMORY} option. However, this value was not written to the .frm file, so that a subsequent CREATE TABLE ... LIKE for the table did not include that option.

Also, ALTER TABLE of a table that had a tablespace incorrectly destroyed the tablespace. (Bug #60111, Bug #11766883, Bug #34047, Bug #11747789)

The server permitted max_allowed_packet to be set lower than net_buffer_length, which does not make sense because max_allowed_packet is the upper limit on net_buffer_length values. Now a warning occurs and the value remains unchanged. (Bug #59959, Bug #11766769)

A missing variable initialization for Item_func_set_user_var objects could raise an assertion. (Bug #59527, Bug #11766424)

When the server was started with the --skip-innodb option, it initialized the have_innodb system variable to YES rather than DISABLED. (Bug #59393, Bug #11766306)

In Item_func_month::val_str(), a Valgrind warning for a too-late NULL value check was corrected. (Bug #59166, Bug #11766126)

In Item::get_date, a Valgrind warning for a missing NULL value check was corrected. (Bug #59164, Bug #11766124)

In extract_date_time(), a Valgrind warning for a missing end-of-string check was corrected. (Bug #59151, Bug #11766112)

In string context, the MIN() and MAX() functions did not take into account the unsignedness of a BIGINT UNSIGNED argument. (Bug #59132, Bug #11766094)

In Item_func::val_decimal, a Valgrind warning for a missing NULL value check was corrected. (Bug #59125, Bug #11766087)

In Item_func_str_to_date::val_str, a Valgrind warning for an uninitialized variable was corrected. (Bug #58154, Bug #11765216)

An assertion could be raised in Item_func_int_val::fix_num_length_and_dec() due to overflow for geometry functions. (Bug #57900, Bug #11764994)

With prepared statements, the server could attempt to send result set metadata after the table had been closed. (Bug #56115, Bug #11763413)

With lower_case_table_names=2, resolution of objects qualified by database names could fail. (Bug #50924, Bug #11758687)

SHOW EVENTS did not always show events from the correct database. (Bug #41907, Bug #11751148)

Functionality Added or Changed

Bugs Fixed

InnoDB now permits concurrent reads on a table while creating nonprimary unique indexes. (This was found to create problems and was reverted in 5.5.12.) (Bug #11784056)

Previously, Performance Schema instrumentation for both the binary log and the relay log used these instruments:

wait/io/file/sql/binlog
wait/io/file/sql/binlog_index
wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_index
wait/synch/cond/sql/MYSQL_BIN_LOG::update_cond

Now instrumentation for the relay log uses these instruments, which makes it possible to distinguish binary log and relay log events:

wait/io/file/sql/relaylog
wait/io/file/sql/relaylog_index
wait/synch/mutex/sql/MYSQL_RELAY_LOG::LOCK_index
wait/synch/cond/sql/MYSQL_RELAY_LOG::update_cond

(Bug #59658, Bug #11766528)

MySQL distributions now include an INFO_SRC file that contains information about the source distribution, such as the MySQL version from which it was created. MySQL binary distributions additionally include an INFO_BIN file that contains information about how the distribution was built, such as compiler options and feature flags. In RPM packages, these files are located in the /usr/share/doc/packages/MySQL-server directory. In tar.gz and derived packages, they are located in the Docs directory under the location where the distribution is unpacked. (Bug #42969, Bug #11751935)

Previously, for queries that were aborted due to a sort problem or terminated with KILL in the middle of a sort, the server wrote the message Sort aborted to the error log. Now the server writes more information about the cause of the error. These causes include:

(Bug #30771, Bug #11747102)

A new system variable, max_long_data_size, now controls the maximum size of parameter values that can be sent with the mysql_stmt_send_long_data() C API function. If not set at server startup, the default is the value of the max_allowed_packet system variable. This variable is deprecated. In MySQL 5.6, it is removed and the maximum parameter size is controlled by max_allowed_packet.

For the Windows installer, debug information files and the embedded MySQL server have been removed from the standard MSI distribution file to reduce the download size for the majority of users.

If these files are needed, the Zip distribution must be downloaded separately and be extracted in the installation directory, which is most probably C:\Program Files\MySQL\MySQL Server 5.5 on English systems.

Please note that upon product de-installation, these extracted files from the Zip distribution must be removed from the system manually.

The undocumented SHOW NEW MASTER statement has been removed.

Important Change: The length of the plugin column of the mysql.user system table is increased to 64 characters. This is now the same size as the name column of the mysql.plugin table. (Bug #11766610, Bug #59752)

Partitioning: A problem with a previous fix for poor performance of INSERT ON DUPLICATE KEY UPDATE statements on tables having many partitions caused the handler function for reading a row from a specific index to fail to store the ID of the partition last used. This caused some statements to fail with Can't find record errors. (Bug #59297, Bug #11766232)

References: This issue is a regression of: Bug #52455.

Replication: A failed DROP DATABASE statement could break statement-based replication. (Bug #58381, Bug #11765416)

Two unused test files in storage/ndb/test/sql contained incorrect versions of the GNU Lesser General Public License. The files and the directory containing them have been removed. (Bug #11810224)

References: See also: Bug #11810156.

Division of large numbers could cause stack corruption. (Bug #11792200)

Queries that used COALESCE() with cp1251 strings could result in an “illegal mix of collations” error. (Bug #60101, Bug #11766874)

The mysql_load_plugin() C API function did not clear the previous error. (Bug #60075, Bug #11766854)

An assertion was raised if an XA COMMIT was issued when an XA transaction had already encountered an error (such as a deadlock) that required the transaction to be rolled back. (Bug #59986, Bug #11766788)

On some systems, debug builds of comp_err could fail due to an uninitialized variable. (Bug #59906, Bug #11766729)

The server read one byte too many when trying to process an XML string lacking a closing single quote (') or double quote (") character used as an argument for UpdateXML() or ExtractValue(). (Bug #59901, Bug #11766725)

References: See also: Bug #44332, Bug #11752979.

Attempting to create a spatial index on a CHAR column longer than 31 bytes led to an assertion failure if the server was compiled with safemutex support. (Bug #59888, Bug #11766714)

Aggregation followed by a subquery could produce an incorrect result. (Bug #59839, Bug #11766675)

An incorrect character set pointer passed to my_strtoll10_mb2() caused an assertion to be raised. (Bug #59648, Bug #11766519)

FIND_IN_SET() could work differently in MySQL 5.5 than in 5.1. (Bug #59405, Bug #11766317)

mysqldump did not quote database names in ALTER DATABASE statements in its output, which could cause an error at reload time for database names containing a dash. (Bug #59398, Bug #11766310)

The MYSQL_HOME environment variable was being ignored. (Bug #59280, Bug #11766219)

An invalid pathname argument for the --defaults-extra-file option of MySQL programs caused a program crash. (Bug #59234, Bug #11766184)

On Windows, the authentication_string column recently added to the mysql.user table caused the Configuration Wizard to fail. (Bug #59038, Bug #11766011)

CREATE TRIGGER and DROP TRIGGER can change the prelocking list of stored routines, but the routine cache did not detect such changes, resulting in routine execution with an inaccurate locking list. (Bug #58674, Bug #11765684)

The code for PROCEDURE ANALYSE() had a missing DBUG_RETURN statement, which could cause a server crash in debug builds. (Bug #58140, Bug #11765202)

An assertion was raised if a statement tried to upgrade a metadata lock while there was an active FLUSH TABLE tbl_list WITH READ LOCK statement. Now if a statement tries to upgrade a metadata lock in this situation, the server returns an ER_TABLE_NOT_LOCKED_FOR_WRITE error to the client. (Bug #57649, Bug #11764779)

If a multiple-table update updated a row through two aliases and the first update physically moved the row, the second update failed to locate the row. This resulted in different errors depending on the storage engine, although these errors did not accurately describe the problem:

For MyISAM, which is nontransactional, the update executed first was performed but the second was not. In addition, for two equal multiple-table update statements, one could succeed and the other fail depending on whether the record actually moved, which is inconsistent.

Now such an update returns an error if it will update a table through multiple aliases, and perform an update that may physically move the row in at least one of these aliases. (Bug #57373, Bug #11764529, Bug #55385, Bug #11762751)

SHOW WARNINGS output following EXPLAIN EXTENDED could include unprintable characters. (Bug #57341, Bug #11764503)

In some cases, SHOW WARNINGS returned an empty result when the previous statement failed. (Bug #55847, Bug #11763166)

On Windows, an object in thread local storage could be used before the object was created. (Bug #55730, Bug #11763065)

For a client connected using SSL, the Ssl_cipher_list status variable was empty and did not show the possible cipher types. (Bug #52596, Bug #11760210)

When used to upgrade tables, mysqlcheck (and mysql_upgrade, which invokes mysqlcheck) did not upgrade some tables for which table repair was found to be necessary. In particular, it failed to upgrade InnoDB tables that needed repair, leaving them in a nonupgraded state. This occurred because:

To fix the problem, the following changes were made to CHECK TABLE ... FOR UPGRADE and mysqlcheck. Because mysql_upgrade invokes mysqlcheck, these changes also fix the problem for mysql_upgrade.

(Bug #47205, Bug #11755431)

When CASE ... WHEN arguments had different character sets, 8-bit values could be referenced as utf16 or utf32 values, raising an assertion. (Bug #44793, Bug #11753363)

Bitmap functions used in one thread could change bitmaps used by other threads, raising an assertion. (Bug #43152, Bug #11752069)

C API Notes

Pluggable Authentication

Functionality Added or Changed

Bugs Fixed

Incompatible Change: The shared library version of the client library was increased to 18 to reflect ABI changes, and avoid compatibility problems with the client library in MySQL 5.1. Note that this is an incompatible change between 5.5.10 and earlier 5.5 versions, so client programs that use the 5.5 client library should be recompiled against the 5.5.10 client library. (Bug #60061, Bug #11827366)

MySQL distributions now include auth_socket, a server-side authentication plugin that authenticates clients that connect from the local host through the Unix socket file. The plugin uses the SO_PEERCRED socket option to obtain information about the user running the client program (and thus can be built only on systems that support this option). For a connection to succeed, the plugin requires a match between the login name of the connecting client user and the MySQL user name presented by the client program. For more information, see The Socket Peer-Credential Authentication Plugin. (Bug #59017, Bug #11765993, Bug #9411, Bug #11745104)

MySQL distributions now include mysql_clear_password, a client-side authentication plugin that sends the password to the server without hashing or encryption. Although this is insecure, and thus appropriate precautions should be taken (such as using an SSL connection), the plugin is useful in conjunction with server-side plugins that must have access to the original password in clear text. For more information, see The Cleartext Client-Side Authentication Plugin.

The mysql_upgrade, mysqlbinlog, mysqlcheck, mysqlimport, mysqlshow, and mysqlslap clients now have --default-auth and --plugin-dir options for specifying which authentication plugin and plugin directory to use. (Bug #58139)

Boolean system variables can be enabled at run time by setting them to the value ON or OFF, but previously this did not work at server startup. Now at startup such variables can be enabled by setting them to ON or TRUE, or disabled by setting them to OFF or FALSE. Any other nonnumeric value is invalid. (Bug #46393)

References: See also: Bug #11754743, Bug #51631.

Previously, for queries that were aborted due to a sort problem, the server wrote the message Sort aborted to the error log. Now the server writes more information to provide a more specific message, such as:

Sort aborted: Out of memory (Needed 24 bytes)
Out of sort memory, consider increasing server sort buffer size
Sort aborted: Out of sort memory, consider increasing server sort
  buffer size
Sort aborted: Incorrect number of arguments for FUNCTION test.f1;
  expected 0, got 1

In addition, if the server was started with --log-warnings=2, the server writes information about the host, user, and query. (Bug #36022, Bug #11748358)

mysqldump --xml now displays comments from column definitions. (Bug #13618, Bug #11745324)

Security Fix: A security bug was fixed. (Bug #36544)

Important Change; InnoDB: The libaio library, which has been used on Linux systems since MySQL 5.5.4, is now linked into mysqld dynamically rather than statically. If the library is not already on your Linux system, install it using the appropriate package manager for your distribution. The libaio-dev library is not sufficient; you must have the libaio library. (Bug #11893055, Bug #60544)

InnoDB: Raised the number of I/O requests that each AIO helper thread could process, from 32 to 256. The new limit applies to Linux and Unix platforms; the limit on Windows remains 32. (Bug #59472)

InnoDB: InnoDB returned values for “rows examined” in the query plan that were higher than expected. NULL values were treated in an inconsistent way. The inaccurate statistics could trigger “false positives” in combination with the max_join_size setting, because the queries did not really examine as many rows as reported.

A new configuration option innodb_stats_method lets you specify how NULL values are treated when calculating index statistics. Allowed values are nulls_equal (the default), nulls_unequal and null_ignored. The meanings of these values are similar to those of the myisam_stats_method option. (Bug #30423)

Replication: When using the statement-based logging format, INSERT ON DUPLICATE KEY UPDATE and INSERT IGNORE statements affecting transactional tables that did not fail were not written to the binary log if they did not insert any rows. (With statement-based logging, all successful statements should be logged, whether they do or do not cause any rows to be changed.) (Bug #59338, Bug #11766266)

Replication: Formerly, STOP SLAVE stopped the slave I/O thread first and then stopped the slave SQL thread; thus, it was possible for the I/O thread to stop after replicating only part of a transaction which the SQL thread was executing, in which case—if the transaction could not be rolled back safely—the SQL thread could hang.

Now, STOP SLAVE stops the slave SQL thread first and then stops the I/O thread; this guarantees that the I/O thread can fetch any remaining events in the transaction that the SQL thread is executing, so that the SQL thread can finish the transaction if it cannot be rolled back safely. (Bug #58546, Bug #11765563)

Setting the optimizer_switch system variable to an invalid value caused a server crash. (Bug #59894, Bug #11766719)

DES_DECRYPT() could crash if the argument was not produced by DES_ENCRYPT(). (Bug #59632, Bug #11766505)

The server and client did not always properly negotiate authentication plugin names. (Bug #59453, Bug #11766356)

--autocommit=ON did not work (it set the global autocommit value to 0, not 1). (Bug #59432, Bug #11766339)

A query of the following form returned an incorrect result, where the values for col_name in the result set were entirely replaced with NULL values:

SELECT DISTINCT col_name ... ORDER BY col_name DESC;

(Bug #59308, Bug #11766241)

SHOW PRIVILEGES did not display a row for the PROXY privilege. (Bug #59275, Bug #11766216)

SHOW PROFILE could truncate source file names or fail to show function names. (Bug #59273, Bug #11766214)

DELETE or UPDATE statements could fail if they used DATE or DATETIME values with a year, month, or day part of zero. (Bug #59173)

The ESCAPE clause for the LIKE operator permits only expressions that evaluate to a constant at execution time, but aggregate functions were not being rejected. (Bug #59149, Bug #11766110)

Memory leaks detected by Valgrind, some of which could cause incorrect query results, were corrected. (Bug #59110, Bug #11766075)

There was an erroneous restriction on file attributes for LOAD DATA INFILE. The requirement that a file be located in the database directory or world readable is now that the be located in the database directory or readable by the user account used to run the server. (Bug #59085, Bug #11766052)

The DEFAULT_CHARSET and DEFAULT_COLLATION CMake options did not work. (Bug #58991, Bug #11765967)

An OUTER JOIN query using WHERE col_name IS NULL could return an incorrect result. (Bug #58490, Bug #11765513)

Starting the server with the --defaults-file=file_name option, where the file name had no extension, caused a server crash. (Bug #58455, Bug #11765482)

Outer joins with an empty table could produce incorrect results. (Bug #58422, Bug #11765451)

In debug builds, SUBSTRING_INDEX(FORMAT(...), FORMAT(...)) could cause a server crash. (Bug #58371, Bug #11765406)

When mysqladmin was run with the --sleep and --count options, it went into an infinite loop executing the specified command. (Bug #58221, Bug #11765270)

Some string-manipulating SQL functions use a shared string object intended to contain an immutable empty string. This object was used by the SQL function SUBSTRING_INDEX() to return an empty string when one argument was of the wrong data type. If the string object was then modified by the SQL function INSERT(), undefined behavior ensued. (Bug #58165, Bug #11765225)

Parsing nested regular expressions could lead to recursion resulting in a stack overflow crash. (Bug #58026, Bug #11765099)

The fix for Bug #25192 caused load_defaults() to add an argument separator to distinguish options loaded from option files from those provided on the command line, whether or not the application needed it. (Bug #57953, Bug #11765041)

References: See also: Bug #25192, Bug #11746296.

The mysql client went into an infinite loop if the standard input was a directory. (Bug #57450, Bug #11764598)

Outer joins on a unique key could return incorrect results. (Bug #57034, Bug #11764219)

The expression const1 BETWEEN const2 AND field was optimized incorrectly and produced incorrect results. (Bug #57030, Bug #11764215)

Some RPM installation scripts used a hardcoded value for the data directory, which could result in a failed installation for users who have a nonstandard data directory location. The same was true for other configuration values such as the PID file name. (Bug #56581, Bug #11763817)

On FreeBSD and OpenBSD, the server incorrectly checked the range of the system date, causing legal values to be rejected. (Bug #55755, Bug #11763089)

Sorting using ORDER BY AVG(DISTINCT decimal_col) caused a server crash or incorrect results. (Bug #52123, Bug #11759784)

When using ExtractValue() or UpdateXML(), if the XML to be read contained an incomplete XML comment, MySQL read beyond the end of the XML string when processing, leading to a crash of the server. (Bug #44332, Bug #11752979)

DATE_ADD() and DATE_SUB() return a string if the first argument is a string, but incorrectly returned a binary string. Now they return a character string with a collation of connection_collation. (Bug #31384, Bug #11747221)

Functionality Added or Changed

Bugs Fixed

The mysqladmin and mysqldump clients now have --default-auth and --plugin-dir options for specifying which authentication plugin and plugin directory to use. (Bug #58139, Bug #11765201)

sql_priv.h now includes an OPTION_ALLOW_BATCH flag for the transaction_allow_batching feature of MySQL Cluster. (Bug #57604)

Boolean system variables can be enabled at run time by setting them to the value ON or OFF, but previously this did not work at server startup. Now at startup such variables can be enabled by setting them to ON or TRUE. Any other nonnumeric value is interpreted as OFF. (Bug #46393 improves on this such that ON, TRUE, OFF, and FALSE are recognized, and other values are invalid.) (Bug #51631, Bug #11759326)

References: See also: Bug #46393, Bug #11754743.

In the audit plugin interface, the MYSQL_AUDIT_CONNECTION_CLASS event class was added, and the MYSQL_AUDIT_GENERAL_STATUS subclass was added to the MYSQL_AUDIT_GENERAL_CLASS event class. The new symbol definitions can be found in the plugin_audit.h header file.

Security Fix: A security bug was fixed. (Bug #57952)

Performance; InnoDB: An UPDATE statement for an InnoDB table could be slower than necessary if it changed a column covered by a prefix index, but did not change the prefix portion of the value. The fix improves performance for InnoDB 1.1 in MySQL 5.5 and higher, and the InnoDB Plugin for MySQL 5.1. (Bug #58912, Bug #11765900)

Performance; InnoDB: Synchronization inside InnoDB frequently involves the use of spin loops: while waiting, InnoDB executes a tight loop of instructions repeatedly to avoid having the InnoDB process and threads be rescheduled by the operating system. If the spin loops are executed too quickly, system resources are wasted, imposing a performance penalty on transaction throughput. Most modern processors implement the PAUSE instruction for use in spin loops, so the processor can be more efficient.

InnoDB now uses the PAUSE instruction in its spin loops on all platforms where such an instruction is available. Previously, InnoDB used the PAUSE instruction only on Windows systems. Use of the PAUSE instruction increases overall performance with CPU-bound workloads, and provides the added benefit of minimizing power consumption during the execution of the spin loops. (Bug #58666)

Performance: Queries involving InnoDB tables in the INFORMATION_SCHEMA tables TABLE_CONSTRAINTS, KEY_COLUMN_USAGE, or REFERENTIAL_CONSTRAINTS were slower than necessary because statistics were rechecked more often than required, even more so when many foreign keys were present. The improvement to this may be of particular benefit to users of MySQL Enterprise Monitor with many monitored servers or tens of thousands of tables. (Bug #43818, Bug #11752585)

Incompatible Change: When auto_increment_increment is greater than one, values generated by a bulk insert that reaches the maximum column value could wrap around rather producing an overflow error.

As a consequence of the fix, it is no longer possible for an auto-generated value to be equal to the maximum BIGINT UNSIGNED value. It is still possible to store that value manually, if the column can accept it. (Bug #39828, Bug #11749800)

Important Change; Partitioning: Date and time functions used as partitioning functions now have the types of their operands checked; use of a value of the wrong type is now disallowed in such cases. In addition, EXTRACT(WEEK FROM col_name), where col_name is a DATE or DATETIME column, is now disallowed altogether because its return value depends on the value of the default_week_format system variable. (Bug #54483, Bug #11761948)

References: See also: Bug #57071, Bug #11764255.

InnoDB; Partitioning: The partitioning handler did not pass locking information to a table's storage engine handler. This caused high contention and thus slower performance when working with partitioned InnoDB tables. (Bug #59013)

InnoDB: The presence of a double quotation mark inside the COMMENT field for a column could prevent a foreign key constraint from being created properly. (Bug #59197, Bug #11766154)

InnoDB: When multiple InnoDB buffer pools were enabled, SHOW ENGINE INNODB statements displayed information about each one, but not summary information combining statistics for the entire buffer pool subsystem. Now, the aggregated information is displayed in the BUFFER POOL AND MEMORY section, and information about individual buffer pool instances is displayed in a new INDIVIDUAL BUFFER POOL INFO section. (Bug #58461)

InnoDB: The command to create a debug build (cmake -DWITH_DEBUG ...) now automatically sets the InnoDB debugging flag UNIV_DEBUG on all platforms. Formerly, the UNIV_DEBUG flag might not be set for Windows platforms with Visual Studio and not on OS X with Xcode. (Bug #58279)

InnoDB: In InnoDB status output, the value for I/O sum[] could be incorrect, displayed as a very large number. (Bug #57600)

InnoDB: The server could crash with an assertion error, if a stored procedure, stored function, or trigger modified one InnoDB table containing an auto-increment column, and dropped another InnoDB table containing an auto-increment column. (Bug #56228)

InnoDB: It was not possible to query the information_schema.INNODB_TRX table while other connections were running queries involving BLOB types. (Bug #55397, Bug #11762763)

InnoDB: When the lower_case_table_names variable was set to 2, InnoDB could fail to restore a mysqldump dump of a table with foreign key constraints involving case-sensitive names. (Bug #55222)

InnoDB: The OPTIMIZE TABLE statement reset the auto-increment counter for an InnoDB table. Now the auto-increment value is preserved across this operation. (Bug #18274)

Partitioning: Failed ALTER TABLE ... TRUNCATE PARTITION statements were written to the binary log. (Bug #58147)

Partitioning: Failed ALTER TABLE ... PARTITION statements could cause memory leaks. (Bug #56380, Bug #11763641)

References: See also: Bug #46949, Bug #11755209, Bug #56996, Bug #11764187.

Replication: While an INSERT DELAYED statement with a single inserted value does not return any visible warnings, such a warning could be still written into the error log. (Bug #57666, Bug #11764793)

References: See also: Bug #49567.

Replication: When closing a session that used temporary tables, binary logging could sometimes fail with a spurious Failed to write the DROP statement for temporary tables to binary log. (Bug #57288)

Replication: Due to changes made in MySQL 5.5.3, settings made in the binlog_cache_size and max_binlog_cache_size server system variables affected both the binary log statement cache (also introduced in that version) and the binary log transactional cache (formerly known simply as the binary log cache). This meant that the resources used as a result of setting either or both of these variables were double the amount expected. To rectify this problem, these variables now affect only the transactional cache. The fix for this issue also introduces two new system variables binlog_stmt_cache_size and max_binlog_stmt_cache_size, which affect only the binary log statement cache.

In addition, the Binlog_cache_use status variable was incremented whenever either cache was used, and Binlog_cache_disk_use was incremented whenever the disk space from either cache was used, which caused problems with performance tuning of the statement and transactional caches, because it was not possible to determine which of these was being exceeded when attempting to troubleshoot excessive disk seeks and related problems. This issue is solved by changing the behavior of these two status variables such that they are incremented only in response to usage of the binary log transactional cache, as well as by introducing two new status variables Binlog_stmt_cache_use and Binlog_stmt_cache_disk_use, which are incremented only by usage of the binary log statement cache.

The behavior of the max_binlog_cache_size system variable with regard to active sessions has also been changed to match that of the binlog_cache_size system variable: Previously, a change in max_binlog_cache_size took effect in existing sessions; now, as with a change in binlog_cache_size, a change in max_binlog_cache_size takes effect only in sessions begun after the value was changed.

For more information, see System Variables Used with Binary Logging, and Server Status Variables. (Bug #57275, Bug #11764443)

Replication: By default, a value is generated for an AUTO_INCREMENT column by inserting either NULL or 0 into the column. Setting the NO_AUTO_VALUE_ON_ZERO server SQL mode suppresses this behavior for 0, so that it occurs only when NULL is inserted into the column.

This behavior is also followed on a replication slave (by the slave SQL thread) when applying events that have been logged on the master using the statement-based format. However, when applying events that had been logged using the row-based format, NO_AUTO_VALUE_ON_ZERO was ignored, which could lead to an assertion.

To fix this issue, the value of an AUTO_INCREMENT column is no longer generated when applying an event that was logged using the row-based row format, as this value is already contained in the changes applied on the slave. (Bug #56662)

Replication: The Binlog_cache_use and Binlog_cache_disk_use status variables were incremented twice by a change to a table using a transactional storage engine. (Bug #56343, Bug #11763611)

References: This issue is a regression of: Bug #50038.

Replication: The BINLOG statement modified the values of session variables, which could lead to problems with operations such as point-in-time recovery. One such case occurred when replaying a row-based binary log which relied on setting foreign_key_checks = OFF at the session level to create and populate a set of InnoDB tables having foreign key constraints. (Bug #54903)

Replication: mysqlbinlog printed USE statements to its output only when the default database changed between events. To illustrate how this could cause problems, suppose that a user issued the following sequence of statements:

CREATE DATABASE mydb;
USE mydb;
CREATE TABLE mytable (column_definitions);
DROP DATABASE mydb;
CREATE DATABASE mydb;
USE mydb;
CREATE TABLE mytable (column_definitions);

When played back using mysqlbinlog, the second CREATE TABLE statement failed with Error: No Database Selected because the second USE statement was not played back, due to the fact that a database other than mydb was never selected.

This fix ensures that mysqlbinlog outputs a USE statement whenever it reads one from the binary log. (Bug #50914, Bug #11758677)