MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
Pre-General Availability Draft: 2017-07-17
This section lists server variables, status variables, and options that were added for the first time, have been deprecated, or have been removed in MySQL 8.0.
Where applicable, separate lists have been provided—for variables and options which have been added, removed, or deprecated —within each section.
The following system variables, status variables, and options are new in MySQL 8.0, and have not been included in any previous release series.
group_replication_member_weight: Chance of this member being elected as primary. Added in MySQL 8.0.2.group_replication_flow_control_hold_percent: Defines what percentage of the group quota remains unused. Added in MySQL 8.0.2.group_replication_flow_control_max_commit_quota: Defines the maximum flow control quota of the group. Added in MySQL 8.0.2.group_replication_flow_control_member_quota_percent: Defines the percentage of the quota that a member should assume is available for itself when calculating the quotas. Added in MySQL 8.0.2.group_replication_flow_control_min_quota: Controls the lowest flow control quota that can be assigned to a member. Added in MySQL 8.0.2.group_replication_flow_control_min_recovery_quota: Controls the lowest quota that can be assigned to a member because of another recovering member in the group. Added in MySQL 8.0.2.group_replication_flow_control_period: Defines how many seconds to wait between flow control iterations. Added in MySQL 8.0.2.group_replication_flow_control_release_percent: Defines how the group quota should be released when flow control no longer needs to throttle the writer members. Added in MySQL 8.0.2.Acl_cache_items_count: Number of cached privilege objects. Added in MySQL 8.0.0.binlog_expire_logs_seconds: Purge binary logs after this many seconds; effects are additive with expire_logs_days. Added in MySQL 8.0.1.binlog_row_metadata: Configures the amount of table related metadata binary logged when using row-based logging.. Added in MySQL 8.0.1.binlog_transaction_dependency_tracking: Source of dependency information (commit timestamps or transaction write sets) from which to assess which transactions can be executed in parallel by slave's multi-threaded applier.. Added in MySQL 8.0.1.binlog_transaction_dependency_history_size: Number of row hashes kept for looking up transaction that last updated some row.. Added in MySQL 8.0.1.Com_alter_user_default_role: Count of ALTER USER ... DEFAULT ROLE statements. Added in MySQL 8.0.0.Com_create_role: Count of CREATE ROLE statements. Added in MySQL 8.0.0.Com_drop_role: Count of DROP ROLE statements. Added in MySQL 8.0.0.Com_grant_roles: Count of GRANT ROLE statements. Added in MySQL 8.0.0.Com_install_component: Count of INSTALL COMPONENT statements. Added in MySQL 8.0.0.Com_revoke_roles: Count of REVOKE ROLES statements. Added in MySQL 8.0.0.Com_set_role: Count of SET ROLE statements. Added in MySQL 8.0.0.Com_uninstall_component: Count of UINSTALL COMPONENT statements. Added in MySQL 8.0.0.histogram_generation_max_mem_size: Maximum memory for creating histogram statistics. Added in MySQL 8.0.2.information_schema_stats: Which table statistics source to use. Added in MySQL 8.0.0.innodb_buffer_pool_debug: Permits multiple buffer pool instances when the buffer pool is less than 1GB in size. Added in MySQL 8.0.0.innodb_checkpoint_disabled: Disables checkpoints so that a deliberate server exit always initiates recovery. Added in MySQL 8.0.2.innodb_redo_log_encrypt: Controls encryption of redo log data for encrypted tablepaces. Added in MySQL 8.0.1.innodb_scan_directories: Defines directories to scan for tablespace files during InnoDB recovery. Added in MySQL 8.0.2.internal_tmp_mem_storage_engine: Defines the storage to use for internal in-memory temporary tables. Added in MySQL 8.0.2.innodb_undo_log_encrypt: Controls encryption of undo log data for encrypted tablepaces. Added in MySQL 8.0.1.original_commit_timestamp: The time when a transaction was committed on the original master. Added in MySQL 8.0.1.performance_schema_error_size: Number of instrumented errors. Added in MySQL 8.0.0.Performance_schema_session_connect_attrs_longest_seen: The size of the longest valid connection attribute buffer seen. Added in MySQL 8.0.0.persisted_globals_load: Whether to load persisted configuration settings. Added in MySQL 8.0.0.schema_definition_cache: Defines the number of schema definition objects that can be kept in the dictionary object cache. Added in MySQL 8.0.0.stored_program_definition_cache: Defines the number of stored program and event definition objects that can be kept in the dictionary object cache. Added in MySQL 8.0.0.tablespace_definition_cache: Defines the number of tablespace definition objects that can be kept in the dictionary object cache. Added in MySQL 8.0.0.temptable_max_ram: Defines the maximum amount of memory that can occupied by the TempTable storage engine before data is stored on disk. Added in MySQL 8.0.2.
The following system variables, status variables, and options have been deprecated in MySQL 8.0.
symbolic-links: Permit symbolic links for MyISAM tables. Deprecated as of MySQL 8.0.2.
The following system variables, status variables, and options have been removed in MySQL 8.0.
bootstrap: Used by mysql installation scripts. Removed in MySQL 8.0.0.Com_alter_db_upgrade: Count of ALTER DATABASE ... UPGRADE DATA DIRECTORY NAME statements. Removed in MySQL 8.0.0.ignore-builtin-innodb: Ignore the built-in InnoDB. Removed in MySQL 8.0.3.ignore-db-dir: Treat directory as nondatabase directory. Removed in MySQL 8.0.0.ignore_db_dirs: Directories treated as nondatabase directories. Removed in MySQL 8.0.0.Innodb_available_undo_logs: Display the total number of InnoDB rollback segments; different from innodb_rollback_segments, which displays the number of active rollback segments. Removed in MySQL 8.0.2.innodb_checksums: Enable InnoDB checksums validation. Removed in MySQL 8.0.0.innodb_disable_resize_buffer_pool_debug: Disables resizing of the InnoDB buffer pool. Removed in MySQL 8.0.0.innodb_file_format: The format for new InnoDB tables. Removed in MySQL 8.0.0.innodb_file_format_check: Whether InnoDB performs file format compatibility checking. Removed in MySQL 8.0.0.innodb_file_format_max: The file format tag in the shared tablespace. Removed in MySQL 8.0.0.innodb_large_prefix: Enables longer keys for column prefix indexes. Removed in MySQL 8.0.0.innodb_locks_unsafe_for_binlog: Force InnoDB not to use next-key locking. Instead use only row-level locking. Removed in MySQL 8.0.0.innodb_stats_sample_pages: Number of index pages to sample for index distribution statistics. Removed in MySQL 8.0.0.innodb_support_xa: Enable InnoDB support for the XA two-phase commit. Removed in MySQL 8.0.0.innodb_undo_logs: Defines the number of undo logs (rollback segments) used by InnoDB; an alias for innodb_rollback_segments. Removed in MySQL 8.0.2.partition: Enable (or disable) partitioning support. Removed in MySQL 8.0.0.show_compatibility_56: Compatibility for SHOW STATUS/VARIABLES. Removed in MySQL 8.0.1.skip-partition: Do not enable user-defined partitioning. Removed in MySQL 8.0.0.Slave_heartbeat_period: The slave's replication heartbeat interval, in seconds. Removed in MySQL 8.0.1.Slave_last_heartbeat: Shows when the latest heartbeat signal was received, in TIMESTAMP format. Removed in MySQL 8.0.1.Slave_received_heartbeats: Number of heartbeats received by a replication slave since previous reset. Removed in MySQL 8.0.1.Slave_retried_transactions: The total number of times since startup that the replication slave SQL thread has retried transactions. Removed in MySQL 8.0.1.Slave_running: The state of this server as a replication slave (slave I/O thread status). Removed in MySQL 8.0.1.sync_frm: Sync .frm to disk on create. Enabled by default. Removed in MySQL 8.0.0.temp-pool: Using this option will cause most temporary files created to use a small set of names, rather than a unique name for each new file. Removed in MySQL 8.0.1.