Process list progression

You certainly know the show process list command that shows you the current list of running queries on your MariaDB instance. Since the Version 5.3 of MariaDB, another option is available that shows you the progression of certain long tasks such as the following:

• ALTER TABLE

• CREATE INDEX

• DROP INDEX

• LOAD DATA IN FILE

• CHECK TABLE

• REPAIR TABLE

• ANALYZE TABLE

• OPTIMIZE TABLE

By default, it's enabled in MariaDB, but your client or driver should be recent enough to support this feature. MariaDB sends back the information to the client every 5 seconds by default.

Here is an example of changing the storage engine of a table:

MariaDB [chapter2]> ALTER TABLE s_explain ENGINE = Aria;
Stage: 1 of 2 'copy to tmp table' 9.09e+03% of stage done

You can see the progression simply by running the ALTER TABLE command. The progression is also available from the processlist command:

MariaDB [(none)]> SHOW PROCESSLIST\G;
[...]
*************************** 2. row ************...