Ow Mun Heng wrote:
On Wed, 2007-09-12 at 09:42 +0100, Richard Huxton wrote:
Well, I suppose you could partition over (month,product) but you
probably don't want to. Sounds fiddly to manage.
Yeah.. well current schema w/ everything in 1 table and the way things
are ordered, normalised design etc, is causing PG to calc stats wrongly
and i get a 1 to 500x ratio between plan and actual analysed rows which
is causing queries to run > 2 hours w/o returning results. (this was
tested w/ on tables w/ only ~3 million rows and joining another table w/
another 3 million data - one to many relationship, I think, is causing
the mis-estimates.)
Well, let's see the query + explain. It's not in one of your previous
posts, is it? PG doesn't know about cross-column correlations, but you
can usually get better than 500x out. Since it's taking > 2 hours to get
a result we'll have to settle for explain rather than explain-analyse.
--
Richard Huxton
Archonet Ltd
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