The INNODB_SYS_INDEXES table provides metadata
about InnoDB indexes, equivalent to the
information in the internal SYS_INDEXES table
in the InnoDB data dictionary.
For related usage information and examples, see Section 14.15.3, “InnoDB INFORMATION_SCHEMA System Tables”.
Table 21.21 INNODB_SYS_INDEXES Columns
| Column name | Description |
|---|---|
INDEX_ID | An identifier for each index that is unique across all the databases in an instance. |
NAME | The name of the index. Most indexes created implicitly by
InnoDB have consistent names but the
index names are not necessarily unique. For example,
PRIMARY for a primary key index,
GEN_CLUST_INDEX for the index
representing a primary key when one is not specified, and
ID_IND, FOR_IND, and
REF_IND for foreign key constraints. |
TABLE_ID | An identifier representing the table associated with the index; the same
value from INNODB_SYS_TABLES.TABLE_ID. |
TYPE | A numeric identifier signifying the kind of index. 0 = Secondary Index, 1 = Clustered Index, 2 = Unique Index, 3 = Primary Index, 32 = Full-text Index. |
N_FIELDS | The number of columns in the index key. For the
GEN_CLUST_INDEX indexes, this value is
0 because the index is created using an artificial value
rather than a real table column. |
PAGE_NO | The root page number of the index B-tree. For full-text indexes, the
PAGE_NO field is unused and set to -1
(FIL_NULL) because the full-text index
is laid out in several B-trees (auxiliary tables). |
SPACE | An identifier for the tablespace where the index resides. 0 means the
InnoDB
system
tablespace. Any other number represents a table
created in
file-per-table
mode with a separate .ibd file. This
identifier stays the same after a
TRUNCATE TABLE statement.
Because all indexes for a table reside in the same
tablespace as the table, this value is not necessarily
unique. |
Example:
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES WHERE TABLE_ID = 74\G
*************************** 1. row ***************************
INDEX_ID: 116
NAME: GEN_CLUST_INDEX
TABLE_ID: 74
TYPE: 1
N_FIELDS: 0
PAGE_NO: 3
SPACE: 60
*************************** 2. row ***************************
INDEX_ID: 117
NAME: i1
TABLE_ID: 74
TYPE: 0
N_FIELDS: 1
PAGE_NO: 4
SPACE: 60
Notes:
Use DESCRIBE or
SHOW COLUMNS to view additional
information about the columns of this table including data
types and default values.
You must have the PROCESS
privilege to query this table.