From: Shaun Thomas <sthomas@optionshouse.com>
To: Aaron Weber <aweber@comcast.net>
To: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: how to improve perf of 131MM row table?
Date: Wed, 25 Jun 2014 16:55:29 -0500
Message-ID: <53AB4551.4070207@optionshouse.com> (raw)
In-Reply-To: <1801a5d4-c3f1-4c0c-9c2c-ffb9d7f723a3@email.android.com>
References: <53AB2CB1.8080201@comcast.net>
<53AB35CC.10202@optionshouse.com>
<1801a5d4-c3f1-4c0c-9c2c-ffb9d7f723a3@email.android.com>
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On 06/25/2014 04:40 PM, Aaron Weber wrote:
> In the meantime, I guess I wasn't clear about some other particulars
> The query's where clause is only an "IN", with a list of id's (those
> I mentioned are the PK), and the join is explicitly on the PK (so,
> indexed).
Indexed doesn't mean indexed if the wrong datatypes are used. We need to
see the table and index definitions, and a sample query with EXPLAIN
ANALYZE output.
> An IN with 50 int values took 23sec to return (by way of example).
To me, this sounds like a sequence scan, or one of your key matches so
many rows, the random seeks are throwing off your performance. Of
course, I can't confirm that without EXPLAIN output.
--
Shaun Thomas
OptionsHouse, LLC | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@optionshouse.com
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To: pgsql-performance@postgresql.org
Cc: sthomas@optionshouse.com, aweber@comcast.net
Subject: Re: how to improve perf of 131MM row table?
In-Reply-To: <53AB4551.4070207@optionshouse.com>
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