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Re: PG8.2.1 choosing slow seqscan over idx scan

From: "Chad Wagner" <chad(dot)wagner(at)gmail(dot)com>
To: "Jeremy Haile" <jhaile(at)fastmail(dot)fm>
Cc: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-performance(at)postgresql(dot)org
Subject: Re: PG8.2.1 choosing slow seqscan over idx scan
Date: 2007-01-16 22:44:53
Message-ID: 81961ff50701161444l3f932755m5a6e15ad2d948130@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-performance
On 1/16/07, Jeremy Haile <jhaile(at)fastmail(dot)fm> wrote:
>
> Even if unrelated, do you think disk fragmentation would have negative
> effects?  Is it worth trying to defragment the drive on a regular basis
> in Windows?
>

Out of curiosity, is this table heavily updated or deleted from?  Perhaps
there is an unfavorable "correlation" between the btree and data?  Can you
dump the results of

select attname, null_frac, avg_width, n_distinct, correlation from pg_stats
where tablename = 'transaction_facts'




-- 
Chad
http://www.postgresqlforums.com/

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