Incorrect key file for table '/tmp/#sql_3c51_0.MYI'; try to repair it [duplicate]

Answer 1

I used this following command and the error was gone:

mysqlcheck --all-databases -r #repair

I got this solution from the cpanel forum

Answer 2

The problem is caused by the lack of disk space in /tmp folder. The /tmp volume is used in queries that require to create temporary tables. These temporary tables are in MyISAM format even if the query is using only tables with InnoDB.

Here are some solutions:

• optimize the query so it will not create temporary tables (rewrite the query, split it in multiple queries, or add proper indexes, analyze the execution plan with pt-query-digest and EXPLAIN <query>) See this Percona article about temporary tables.
• optimize MySQL so it will not create temporary tables (sort_buffer_size, join_buffer_size). See: https://dba.stackexchange.com/questions/53201/mysql-creates-temporary-tables-on-disk-how-do-i-stop-it
• make tables smaller. If possible, delete unneeded rows
• use data types that take less space
• add more disk space on the volume where /tmp folder resides
• change the temp folder user by mysql by setting the TMPDIR environment variable prior to mysqld start-up. Point TMPDIR to a folder on a disk volume that has more free space. You can also use tmpdir option in /etc/my.cnf or --tmpdir in the command line of the mysqld service. See: B.5.3.5 Where MySQL Stores Temporary Files

Answer 3

Do these steps

Stop mysql service

rename the .myi file to x.old

Start mysql

REPAIR all the tables in query ,MySQL will rebuild key file

Answer 4

Check your database server that you have enough disk space on it. If disks are full this error is displayed. Now, which folders you should look at it depends on your setup.

Answer 5

Restart MySQL service using this command line /etc/init.d/mysqld restart in terminal.

Answer 6

Check the location of your tmp dir, by running df -h. Make sure there's enough space to grow the temp file, it could be several gigs.

Edit: If you have enough free space, I'd check to make sure every column you're indexing on or including in the WHERE clause is indexed.