Re: a MySQL to PostgreSQL successful port, but performance is bad... - Mailing list pgsql-novice

From Tom Lane
Subject Re: a MySQL to PostgreSQL successful port, but performance is bad...
Date
Msg-id 4912.1149030384@sss.pgh.pa.us
Whole thread Raw
In response to a MySQL to PostgreSQL successful port, but performance is bad...  (Jim Brown <jimbrown32rb@yahoo.com>)
List pgsql-novice
Jim Brown <jimbrown32rb@yahoo.com> writes:
> Here's my problem, though: queries in mySQL are almost
> instantaneous, whereas those same queries in
> PostgreSQL can take four seconds or more - even when
> I'm hitting a table with only one row. I'll bet I have
> something misconfigured, but I'm a newbie FNG, and I
> don't yet know my way around yet.

Two things to check right away: have you ANALYZEd all your tables, and
did you remember to make all the same indexes you have in the MySQL
database?  (I believe PG and MySQL have slightly different ideas about
when to make indexes automatically.)  psql's "\d table" command is a
handy way to verify what indexes you have on a table.

If you're still having problems, feel free to post EXPLAIN ANALYZE
output for the problem queries on pgsql-performance.  Also mention
which postgresql.conf settings you're using.

            regards, tom lane

pgsql-novice by date:

Previous
From: Richard Broersma Jr
Date:
Subject: Re: What is PostgreSQL 8.0 ??
Next
From: Richard Broersma Jr
Date:
Subject: Re: a MySQL to PostgreSQL successful port, but performance is bad...