Re: Plan time Improvement - 64bit bitmapset

On 06/03/2009 08:57 PM, Gregory Stark wrote:
> "Kevin Grittner"<Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
>> Andres Freund<andres(at)anarazel(dot)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