piatkow - 9:33 pm on Jan 15, 2013 (gmt 0)

I don't know MYSQL as my DBA background was on big boxes but a classic way, if there are no referential integrity issues, is to create the temp table as identical to the original and then rename the pair of them.

If an update takes 3 hours then it sounds as if you need a faster connection or a faster box (or both).