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CHECK TABLE  works for InnoDB , MyISAM , ARCHIVE , and CSV  tables. 

Before running CHECK TABLE  on InnoDB  tables, see CHECK TABLE Usage Notes for InnoDB Tables. 

CHECK TABLE  is supported for partitioned tables, and you can use ALTER TABLE ... CHECK PARTITION  to check one or more partitions; for more information, see Section 13.1.9, “ALTER TABLE Statement” , and Section 24.3.4, “Maintenance of Partitions” . 

## CHECK TABLE Output 

CHECK TABLE  ignores virtual generated columns that are not indexed. 

•CHECK TABLE Output 

•Checking Version Compatibility 

•Checking Data Consistency 

•CHECK TABLE Usage Notes for InnoDB Tables 

•CHECK TABLE Usage Notes for MyISAM Tables 

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The statement might produce many rows of information for each checked table. The last row has a Msg_type  value of status  and the Msg_text  normally should be OK . Table is already up to date  means that the storage engine for the table indicated that there was no need to check the table. 

## Checking Version Compatibility 

The FOR UPGRADE  option checks whether the named tables are compatible with the current version of MySQL. With FOR UPGRADE , the server checks each table to determine whether there have been any incompatible changes in any of the table’s data types or indexes since the table was created. If not, the check succeeds. Otherwise, if there is a possible incompatibility, the server runs a full check on the table (which might take some time). 

Incompatibilities might occur because the storage format for a data type has changed or because its sort order has changed. Our aim is to avoid these changes, but occasionally they are necessary to correct problems that would be worse than an incompatibility between releases. 

FOR UPGRADE  discovers these incompatibilities: 

•The indexing order for end-space in TEXT  columns for InnoDB  and MyISAM  tables changed between MySQL 4.1 and 5.0. 

•The storage method of the new DECIMAL  data type changed between MySQL 5.0.3 and 5.0.5. 

•Changes are sometimes made to character sets or collations that require table indexes to be rebuilt. For details about such changes, see Section 2.11.4, “Changes in MySQL 8.0” . For information about rebuilding tables, see Section 2.11.13, “Rebuilding or Repairing Tables or Indexes” . 

