Re: Why should such a simple query over indexed columns be so slow?

From: Alessandro Gagliardi <alessandro(at)path(dot)com>
To: Josh Berkus <josh(at)agliodbs(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Why should such a simple query over indexed columns be so slow?
Date: 2012-01-30 21:39:14
Message-ID: CAAB3BBLdJ2U2v9LJ-q6r5HUwzmoKavOukRuO4H=yVH1YcSvCdQ@mail.gmail.com
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On Mon, Jan 30, 2012 at 1:25 PM, Josh Berkus <josh(at)agliodbs(dot)com> wrote:

> You can do "SHOW random_page_cost" yourself right now, too.
>
> 4

I also tried "SHOW seq_page_cost" and that's 1.

Looking at
http://www.postgresql.org/docs/current/static/runtime-config-query.html#GUC-RANDOM-PAGE-COSTI
wonder if I should try reducing random_page_cost?

Something that might help when it comes to advice on performance tuning is
that this database is used only for analytics. It's essentially a partial
replication of a production (document-oriented) database. So a lot of
normal operations that might employ a series of sequential fetches may not
actually be the norm in my case. Rather, I'm doing a lot of counts on data
that is typically randomly distributed.

Thanks,

-Alessandro

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