[thelist] SQL
Fred Jones
fredthejonester at gmail.com
Sun Mar 29 09:56:24 CDT 2009
Just sharing today's lesson this Sunday morning. I tried using this:
UPDATE contact SET xxx='yyy'
WHERE id IN (SELECT contact_id FROM temp)
and it ran on 100% CPU for a few minutes before I killed it. Then I
wrote it like this"
UPDATE contact
LEFT JOIN temp ON temp.contact_id = contact .id
SET xxx='yyy'
WHERE temp.contact_id IS NOT NULL;
and MySQL did 25K rows in a few seconds. :)
Rock on.
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