Tag Archives: MyISAM

07 Dec

corrupted / crashed MyISAM + mysql_repair_threads = stuck “Repair with N threads”

In this post we’re going to look at how changing MySQL variable mysql_repair_threads for betterment of a repair table command became root cause of an instance reboot. Also how repair with n threads message tracks down to this.

MyISAM is notorious for table crashes and always need a table repair as a quick remedy.

 Table 'myisam_table' is marked as crashed and should be repaired.

After seeing above error we quickly jump on to one of the following

 repair table myisam_table
 myisamchk -r -q myisam_table

Ofcourse there are more options but that’s not something we’re talking here.

Once this become regular and/or table is large, we look forward to speedup the operation. Then stands out one variable that comes as a ray of hope: mysql_repair_threads
As MySQL documentation says “for value greater than 1, MyISAM table indexes are created in parallel (each index in its own thread) during the Repair by sorting process.” Read More

-- Kedar Vaijanapurkar --