| From: | Kyle <kaf(at)nwlink(dot)com> |
|---|---|
| To: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: poor performance on 7.1 vs 7.0 |
| Date: | 2001-05-08 20:28:09 |
| Message-ID: | 15096.22233.26903.252430@ip146.usw5.rb1.bel.nwlink.com |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | 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(at)nwlink(dot)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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