Documentation Home
MySQL 8.0 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 37.9Mb
PDF (A4) - 37.9Mb
PDF (RPM) - 32.9Mb
HTML Download (TGZ) - 8.0Mb
HTML Download (Zip) - 8.1Mb
HTML Download (RPM) - 6.9Mb
Man Pages (TGZ) - 132.7Kb
Man Pages (Zip) - 188.9Kb
Info (Gzip) - 3.4Mb
Info (Zip) - 3.4Mb
Excerpts from this Manual

MySQL 8.0 Reference Manual  /  ...  /  The INFORMATION_SCHEMA INNODB_TABLESTATS View


The INNODB_TABLESTATS 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 corresponding to 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 not aged out of the table cache. Tables for which persistent stats are available are always represented in this view.

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

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

Table 24.28 INNODB_TABLESTATS Columns

Column name Description
TABLE_ID An identifier representing the table for which statistics are available, using the same value as INNODB_TABLES.TABLE_ID.
NAME The name of the table, using the same value as INNODB_TABLES.NAME.
STATS_INITIALIZED The value is Initialized if the statistics are already collected, Uninitialized if not.
NUM_ROWS The current estimated number of rows in the table. Updated after each DML operation. Could be imprecise if uncommitted transactions are inserting into or deleting from the table.
CLUST_INDEX_SIZE Number of pages on disk that store the clustered index, which holds the InnoDB table data in primary key order. This value might be null if no statistics are collected yet for the table.
OTHER_INDEX_SIZE Number of pages on disk that store all secondary indexes for the table. This value might be null if no statistics are collected yet for the table.
MODIFIED_COUNTER The number of rows modified by DML operations, such as INSERT, UPDATE, DELETE, and also cascade operations from foreign keys. This column is reset each time table statistics are recalculated
AUTOINC The next number to be issued for any auto-increment-based operation. The rate at which the AUTOINC value changes depends on how many times auto-increment numbers have been requested and how many numbers are granted per request.
REF_COUNT When this counter reaches zero, the table metadata can be evicted from the table cache.


*************************** 1. row ***************************
         TABLE_ID: 71
             NAME: test/t1
         NUM_ROWS: 1
          AUTOINC: 0
        REF_COUNT: 1


  • This table is primarily useful for expert-level performance monitoring, or when developing performance-related extensions for MySQL.

  • 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.

User Comments
Sign Up Login You must be logged in to post a comment.