Re: Optimizer bug??

From: Gaetano Mendola <mendola(at)bigfoot(dot)com>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Optimizer bug??
Date: 2004-05-25 15:17:57
Message-ID: c8vo3q$4qp$1@floppy.pyrenet.fr
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Ismail Kizir wrote:

> Gaetano,
>
> I've changed my settings as :
>
> #fsync = true # turns forced synchronization on or off
> #wal_sync_method = fsync # the default varies across platforms:
> #effective_cache_size = 1000 # typically 8KB each
> random_page_cost = 2 # units are one sequential page fetch cost
> cpu_tuple_cost = 0.009 # (same)
> cpu_index_tuple_cost = 0.0009 # (same)
> cpu_operator_cost = 0.0025 # (same)
> # fsync, fdatasync, open_sync, or
> open_datasync
> #wal_buffers = 8 # min 4, 8KB each
>
> But it still doesn't optimize for that range.
> Finally, i've set seq_scan off and, it works now.
> But i think, there must be a way to handle those settings automatically for
> cpu, ram and hdd settings(is it a sweet dream??)

Did you SIGHUP the postmaster after ?

You can change these settings also from command line, what you have to
do is decrease the cost of the index scan till is less of the sequential
scan cost.

Good luck.

Regards
Gaetano Mendola

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Andrew Dunstan 2004-05-25 15:40:36 Re: [HACKERS] pg_ctl.c
Previous Message Tom Lane 2004-05-25 14:05:40 Re: Timezone fun (bugs and a request)