Re: [GENERAL] eliminating records not in (select id ... so SLOW?

[Daniel Verite]

        Ivan Sergio Borgonovo wrote:

But what if I *really* had to execute that query?
Any other magic I could play to speed it up?

A trick that is sometimes spectacularly efficient is to rewrite the 
query to use an outer join instead of NOT IN.

Try:

DELETE FROM table1 WHERE id IN 
(SELECT table1.id FROM table1 LEFT JOIN table2 ON table1.id=table2.id 
WHERE table2.id IS NULL)


Best regards,
--
Daniel
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