Re: BUG #5165: Poor performance with Left-join where right side does not exist

assaf lehr <assaf_lehr(at)yahoo(dot)com> wrote:
> From: Robert Haas <robertmhaas(at)gmail(dot)com>

>> EXPLAIN output would be a good place to start, and EXPLAIN ANALYZE
>> for the queries that run quickly enough that you can let them run
>> to completion.

> let me explain it better.
> [hand-waving and pseudo-code]

People would like to help you, but you're not providing enough
information to let them. If you can show the actual tables involved
in a slow query, the actual query, and the output you get when you run
the query with EXPLAIN ANALYZE in front of the query (or just EXPLAIN
if the EXPLAIN ANALYZE can't run to completion in an acceptable amount
of time); then people will probably be able to help more.

It's also good to include the output of SELECT version(); and
information on the OS, hardware, and the contents of your
postgresql.conf file (excluding comments).

-Kevin