Query planner problem

On Sat, 9 Mar 2002, Crash Dummy wrote:

Hi,

I've moved a database onto a much faster machine but for some reason the
query planner is opting to use seq scan methods rather than the indexes.

This is a very large database without the indexes the performance is dire -
the new machine is a 2Ghz P4 with 1GB RAM, the old machine is a 900Mhz P3
with 512Mb Ram.

Any idea why this is happening adn what I can do to solve the problem ? I've
tried dropping & rebuilding the indexes, vacuum analyze etc but to no
effect.

What do the schema and queries look like, and what does explain (explain
analyze if you've got 7.2) show for them?

"Crash Dummy" <crash.dummy@ntlworld.com> writes:

Hi,

I've moved a database onto a much faster machine but for some reason the
query planner is opting to use seq scan methods rather than the indexes.

This is a very large database without the indexes the performance is dire -
the new machine is a 2Ghz P4 with 1GB RAM, the old machine is a 900Mhz P3
with 512Mb Ram.

Any idea why this is happening adn what I can do to solve the problem ? I've
tried dropping & rebuilding the indexes, vacuum analyze etc but to no
effect.

Post your schema and EXPLAIN output for the problem queries.

-Doug
--
Doug McNaught Wireboard Industries http://www.wireboard.com/

Custom software development, systems and network consulting.
Java PostgreSQL Enhydra Python Zope Perl Apache Linux BSD...

Crash Dummy wrote:

Hi,

I've moved a database onto a much faster machine but for some reason the
query planner is opting to use seq scan methods rather than the indexes.

This is a very large database without the indexes the performance is dire -
the new machine is a 2Ghz P4 with 1GB RAM, the old machine is a 900Mhz P3
with 512Mb Ram.

Any idea why this is happening adn what I can do to solve the problem ? I've
tried dropping & rebuilding the indexes, vacuum analyze etc but to no
effect.

Read the current FAQ item 4.8 on the web site. It is more current and
should answer your question.

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