MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

25.39.27 The INFORMATION_SCHEMA INNODB_TABLESTATS View

The INNODB_TABLESTATS table provides a view of low-level status information about InnoDB tables. This data is used by the MySQL optimizer to calculate which index to use when querying an InnoDB table. This information is derived from in-memory data structures rather than data stored on disk. There is no corresponding internal InnoDB system table.

InnoDB tables are represented in this view if they have been opened since the last server restart and have not aged out of the table cache. Tables for which persistent stats are available are always represented in this view.

Table statistics are updated only for DELETE or UPDATE operations that modify indexed columns. Statistics are not updated by operations that modify only nonindexed columns.

ANALYZE TABLE clears table statistics and sets the STATS_INITIALIZED column to Uninitialized. Statistics are collected again the next time the table is accessed.

For related usage information and examples, see Section 15.14.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”.

The INNODB_TABLESTATS table has these columns:

Example

mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_TABLESTATS where TABLE_ID = 71\G
*************************** 1. row ***************************
         TABLE_ID: 71
             NAME: test/t1
STATS_INITIALIZED: Initialized
         NUM_ROWS: 1
 CLUST_INDEX_SIZE: 1
 OTHER_INDEX_SIZE: 0
 MODIFIED_COUNTER: 1
          AUTOINC: 0
        REF_COUNT: 1

Notes