Given that the plan doesn't change after an analyze, my guess would be that the first query is hitting cached data, then
you vacuum and that chews though all the cache with its own data pushing the good data out of the cache so it has to
be re-fetched from disk.
If you run the select a 2nd time
Hi, I ran into a similar problem using bigints...
See:
http://www.postgresql.org/docs/7.3/static/datatype.html#DATATYPE-INT
small & big int have to be cast when used in querries... try:
explain select * from db where type=90::smallint and
subtype=70::smallint and date='7/1/2004';
or
explain select
Tom Lane wrote:
Doug Y <[EMAIL PROTECTED]> writes:
Tom Lane wrote:
This might tell you something about how many concurrent backends you've
used, but nothing about how many shared buffers you need.
Thats strange, I know I've had more than 4 concurrent connections on
Tom Lane wrote:
Doug Y <[EMAIL PROTECTED]> writes:
I've seen a couple references to using ipcs to help properly size
shared_buffers.
I have not seen any such claim, and I do not see any way offhand that
ipcs could help.
Directly from:
http://www.varlena.com/varlena/GeneralB
Hello,
I've seen a couple references to using ipcs to help properly size
shared_buffers.
I don't claim to be a SA guru, so could someone help explain how to
interpret the output of ipcs and how that relates to shared_buffers? How
does one determine the size of the segment arrays? I see the tota
Hello,
We recently upgraded os from rh 7.2 (2.4 kernel) to Suse 9.1 (2.6
kernel), and psql from 7.3.4 to 7.4.2
One of the quirks I've noticed is how the queries don't always have the
same explain plans on the new psql... but that's a different email I think.
My main question is I'm trying
Hello,
(note best viewed in fixed-width font)
I'm still trying to find where my performance bottle neck is...
I have 4G ram, PG 7.3.4
shared_buffers = 75000
effective_cache_size = 75000
Run a query I've been having trouble with and watch the output of vmstat
(linux):
$ vmstat 1
procs
nkar wrote:
Doug Y wrote:
Hello,
I've been having some performance issues with a DB I use. I'm trying
to come up with some performance recommendations to send to the "adminstrator".
Ok for what I'm uncertain of...
shared_buffers:
According to http://www.varlena.com/varlen
Hello,
I've been having some performance issues with a DB I use. I'm trying to
come up with some performance recommendations to send to the "adminstrator".
Hardware:
CPU0: Pentium III (Coppermine) 1000MHz (256k cache)
CPU1: Pentium III (Coppermine) 1000MHz (256k cache)
Memory: 3863468 kB (4 GB)
