Large Temporary Tables on Disk With MySQL Server

(Doc ID 1381165.1)

Last updated on AUGUST 21, 2016

Applies to:

MySQL Server - Version 4.0 to 5.6 [Release 4.0 to 5.6]
Information in this document applies to any platform.


This kind of error can also occur when the temporary space fills up and there is no free space :

ERROR 126 (HY000): Incorrect key file for table 'C:\Users\\AppData\Local\T emp\#sqlc28_619_10.MYI'; try to repair it

Please note that the # prefix indicates a temporary table and MYI a MyISAM index file.

See also Incorrect key file for table '%s'; try to repair it


The situation can occur after statistics change, especially when using InnoDB.
Previous fast queries can suddenly use internal temporary space while they were not due to a change in explain plan.


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