Re: High load average with PostgreSQL 7.4.2 on debian/ibm eserver.

eleven@ludojad.itpp.pl wrote:


> Whole config is available here:
> http://ludojad.itpp.pl/~eleven/pg-high-load.conf

effective_cache_size = 4000    # typically 8KB each
#random_page_cost = 4        # units are one sequential page fetch cost
#cpu_tuple_cost = 0.01        # (same)
#cpu_index_tuple_cost = 0.001    # (same)
#cpu_operator_cost = 0.0025    # (same)


These values are too higher for your hardware, try to execute the
explain analyze for the queries that are running on your box and
repeat it lowering these values, I bet postgres is running seq scan
instead of an index scan.

These are the value that I use for a configuration closer to your:


effective_cache_size = 20000
random_page_cost = 2.0
cpu_tuple_cost = 0.005
cpu_index_tuple_cost = 0.0005
cpu_operator_cost = 0.0025


last question, do you use the autovacuum daemon ?
If no => you have to use it
If yes => did you apply the patch that will not fail with
           big tables like yours ?


if you can post the autovacuum daemon log ( last lines ).



Regards
Gaetano Mendola