On Mon, 2003-10-13 at 15:43, David Griffiths wrote:
> Here are part of the contents of my sysctl.conf file (note that I've
> played with values as low as 600000 with no difference)
> kernel.shmmax=1400000000
> kernel.shmall=1400000000
This is only a system-wide limit -- it either allows the shared memory
allocation to proceed, or it does not. Changing it will have no other
effect on the performance of PostgreSQL.
> -> Index Scan using comm_ent_usr_acc_id_i on
> commercial_entity ce (cost=0.00..4787.69 rows=78834 width=24) (actual
> time=0.02..55.64 rows=7991 loops=1)
Interesting that we get this row count estimate so completely wrong
(although it may or may not have anything to do with the actual
performance problem you're running into). Have you run ANALYZE on this
table recently? If so, does increasing this column's statistics target
(using ALTER TABLE ... ALTER COLUMN ... SET STATISTICS) improve the row
count estimate?
-Neil
