On 06/03/2009 08:57 PM, Gregory Stark wrote:
"Kevin Grittner"<kevin.gritt...@wicourts.gov> writes:
Andres Freund<and...@anarazel.de> wrote:
long plan times (minutes and up)
Wow. I thought I had some pretty complex queries, including some
which join using several views, each of which has several joins;
but I've never gone to multiple seconds on plan time (much less
multiple minutes!) without very high statistics targets and many
indexes on the tables. Any rough estimates on those?
My money's still on very large statistics targets. If you have a lot
of columns and 1,000-element arrays for each column that can get big
pretty quickly.
Only a relatively small difference (stat target 10; 1000): 22283.187
23986.504
But that doesn't explain the bitmap ops being important. Hm. Actually
having a lot of columns and then joining a lot of tables could mean
having fairly large bitmapsets.
Some of the views have a large amount of columns (200-400) - none of the
actual tables has many columns though (10 user columns is the biggest I
think).
110 tables containing real data.
The queries include the same tables quite often.
Andres
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