Re: poor performance on 7.1 vs 7.0 - Mailing list pgsql-general

From Kyle
Subject Re: poor performance on 7.1 vs 7.0
Date
Msg-id 15096.22233.26903.252430@ip146.usw5.rb1.bel.nwlink.com
Whole thread Raw
In response to Re: poor performance on 7.1 vs 7.0  (Kyle <kaf@nwlink.com>)
List pgsql-general
To answer my own question, never mind...just read Tom's writeup on how
to get the db-specific profile:
      http://fts.postgresql.org/db/mw/msg.html?mid=32379

-Kyle, off to read more online docs


Kyle wrote:
> When I profile the postmaster do the forked backends also show up in
> the profile?  Or do I need to profile those separately?  (and how?)
>
>
>
>
> Tom Lane wrote:
> > Kyle <kaf@nwlink.com> writes:
> > > I'm getting poor performance on 7.1 as compared to 7.0.
> >
> > Hm.  I don't know why 7.1 might be slower for plain SELECTs (the WAL
> > changes would certainly not affect that).  Could you compile 7.1 for
> > profiling ("make clean; make PROFILE=-pg all" in the src/backend
> > subdirectory should do it) and send along a gprof table for your
> > test run?
> >
> > > I've got a btree index on the first 16 of the data elements, and
> > > explain verifies that the index is used.
> >
> > Simple explain doesn't prove that the index is being fully used ---
> > the display doesn't distinguish how many index columns are actually
> > being looked at.  EXPLAIN VERBOSE output would resolve that doubt.
> >
> >             regards, tom lane
> >


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