Very slow delete on mysql base with subquery

Question

This mysql query is running for around 10 hours and has not finished. Something is horribly wrong.

Two tables (text and spam) are here. Spam stores the ids of spam e

Answer 1

In my experience sub queries are often a cause of slow execution times in SQL statements, therefor I try to avoid them. Try this:

DELETE tname FROM tname INNER JOIN spam ON (tname.old_id = spam.textid);

Disclaimer: This query is not tested, make backups first! :-)