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mysqlsqlquery-optimization

What will happen if I kill a huge MySQL InnoDb DELETE Query?

I'm currently running a DELETE query that is taking a lot longer than expected (already 10hrs!). I would like to kill it through phpmyadmin processes, however am concerned about what might happen. Will the roll-back he automatically does take a lot of time also? Current query status shows "updating".

Solution

  • It depends on the stage your query is in right now. But generally rollback takes about equal time, sometimes even more than the original operation.

    As per point 2 of this document, it's not really advisable.

    Also, be sure to verify your MySQL version as it has a VERY nasty bug with delete/update queries rollback in some versions as per this article

    Restarting/killing the MySQL process won't help as rollback will resume upon restart.