Re: MSSQL versus Postgres timing

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Joel Fradkin" <jfradkin(at)wazagua(dot)com>
Cc: "'Michael Fuhr'" <mike(at)fuhr(dot)org>, pgsql-sql(at)postgresql(dot)org
Subject: Re: MSSQL versus Postgres timing
Date: 2005-02-01 21:53:23
Message-ID: 19308.1107294803@sss.pgh.pa.us
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"Joel Fradkin" <jfradkin(at)wazagua(dot)com> writes:
> " -> Sort (cost=38119.24..38333.26 rows=85611 width=52) (actual time=20667.645..21031.627 rows=99139 loops=1)"
> " Sort Key: (a.clientnum)::text, a.jobtitleid"
> " -> Seq Scan on tblassociate a (cost=0.00..31105.34 rows=85611 width=52) (actual time=14.768..16024.395 rows=99139 loops=1)"
> " Filter: ((clientnum)::text = 'SAKS'::text)"

The sort steps seem slower than they ought to be. I suspect you ought
to raise sort_mem ... try 10MB instead of 1MB. Also, if you are running
in a locale other than C and don't have a good reason for doing so, it
would be worth trying C locale instead.

The results with enable_seqscan off also suggest that random_page_cost
may be too high for your environment.

BTW, the schema you posted does not match these plans --- there are
indexes referenced in the plans that do not appear in the schema.

regards, tom lane

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