[EMAIL PROTECTED] wrote:
On Thu, Aug 07, 2008 at 10:40:22AM -0700, Steve Midgley wrote:
Have you tried something where you read in all those "IN id's" and then
group them into blocks (of say 1,000 or 10,000 or whatever number works
best)? Then execute:
DELETE FROM a WHERE a.b_id in ([static_list_of_ids])
It may come to something like that, but I figure handing over hubdreds
of static IDs is probably worse for the planner than an expression,
and it's ugly as sin :-)
I tried using "%" for a mod function, but that seems to not be a
universally recognized operator.
Could you not achieve the same result with a LIMIT on subSELECT and
reissue the command until there is nothing to delete?
Is b_id already unique; or should you be using DISTINCT or GROUP BY on
the subSELECT?
DELETE FROM a WHERE a.b_id IN (SELECT DISTINCT id FROM b WHERE second_id
= ? LIMIT 1000)
DELETE FROM a WHERE a.b_id IN (SELECT id FROM b WHERE second_id = ?
GROUP BY id LIMIT 1000)
If you're really desperate; is it possible to alter table 'a' to add
column b_id; populate it; delete your rows without a join; then drop the
column?
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