Re: Confusing performance of specific query - Mailing list pgsql-general

From Tom Lane
Subject Re: Confusing performance of specific query
Date
Msg-id 4208.1186702938@sss.pgh.pa.us
Whole thread Raw
In response to Confusing performance of specific query  (Adam Endicott <leftwing17@gmail.com>)
List pgsql-general
Adam Endicott <leftwing17@gmail.com> writes:
> When I run EXPLAIN ANALYZE on this query, it takes something like
> 1200ms on my desktop (Dual 2GHz G5 Mac - 1.5 GB RAM for reference) and
> about 14000ms on the production server (quad processor, 8 GB RAM,
> running Ubuntu). There are about 500 rows in the movies_movie table,
> and about 16k rows in the movies_moviescreening table. The data is the
> same on both machines. My desktop is running PostgreSQL 8.2.3, and the
> production server is running 8.1.9.

> Since I don't know much about how to diagnose this, I don't know what
> other information to give, so let me know if I've left out something
> crucial.

Uh ... the actual outputs from the two EXPLAIN ANALYZEs, perhaps?

The most likely bets are (1) something different about the
postgresql.conf settings on the two machines, or (2) the 8.2 planner
is smarter than the 8.1 planner and is choosing a better plan.

            regards, tom lane

pgsql-general by date:

Previous
From: Joseph S
Date:
Subject: Re: UPDATES hang every 5 minutes
Next
From: Greg Smith
Date:
Subject: Re: UPDATES hang every 5 minutes