Where is my bottleneck? - Mailing list pgsql-performance

From Arnau Rebassa Villalonga
Subject Where is my bottleneck?
Date
Msg-id 43D67496.2020203@androme.es
Whole thread Raw
Responses Re: Where is my bottleneck?  (Michael Stone <mstone+postgres@mathom.us>)
Re: Where is my bottleneck?  ("Luke Lonergan" <llonergan@greenplum.com>)
Re: Where is my bottleneck?  ("Jim C. Nasby" <jnasby@pervasive.com>)
Re: Where is my bottleneck?  (Richard Huxton <dev@archonet.com>)
List pgsql-performance
Hi all,

   I have a performance problem and I don't know where is my bottleneck.
I have postgresql 7.4.2 running on a debian server with kernel
2.4.26-1-686-smp with two Xeon(TM) at 2.80GHz and 4GB of RAM and a RAID
5 made with SCSI disks. Maybe its not the latest hardware but I think
it's not that bad.

   My problem is that the general performance is not good enough and I
don't know where is the bottleneck. It could be because the queries are
not optimized as they should be, but I also think it can be a postgresql
configuration problem or hardware problem (HDs not beeing fast enough,
not enough RAM, ... )

   The configuration of postgresql is the default, I tried to tune the
postgresql.conf and the results where disappointing, so I left again the
default values.

When I do top I get:
top - 19:10:24 up 452 days, 15:48,  4 users,  load average: 6.31, 6.27, 6.52
Tasks:  91 total,   8 running,  83 sleeping,   0 stopped,   0 zombie
Cpu(s):  24.8% user,  15.4% system,   0.0% nice,  59.9% idle
Mem:   3748956k total,  3629252k used,   119704k free,    57604k buffers
Swap:  2097136k total,    14188k used,  2082948k free,  3303620k cached

   Most of the time the idle value is even higher than 60%.

I know it's a  problem with a very big scope, but could you give me a
hint about where I should look to?


Thank you very much
--
Arnau


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