From: Gregory Stark <stark@enterprisedb.com>
To: Scott Marlowe <scott.marlowe@gmail.com>
Cc: Justin <justin@emproshunts.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: getting estimated cost to agree with actual
Date: Tue, 03 Jun 2008 02:20:10 +0100
Message-ID: <87mym3iab9.fsf@oxford.xeocode.com> (raw)
In-Reply-To: <dcc563d10806021638t6619ef6cw67f2606541cd90f6@mail.gmail.com>
References: <4844696D.20307@emproshunts.com>
<dcc563d10806021638t6619ef6cw67f2606541cd90f6@mail.gmail.com>
"Scott Marlowe" <scott.marlowe@gmail.com> writes:
> On Mon, Jun 2, 2008 at 3:43 PM, Justin <justin@emproshunts.com> wrote:
>>
>> I have noticed that estimated Cost to do the query is way off from Actual.
>
> Well, they're not measured in the same units. estimated costs are in
> terms of the cost to sequentially scan a single tuple, while actual
> costs are in milliseconds.
s/tuple/page/
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
Ask me about EnterpriseDB's On-Demand Production Tuning
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To: pgsql-performance@postgresql.org
Cc: stark@enterprisedb.com, scott.marlowe@gmail.com, justin@emproshunts.com
Subject: Re: getting estimated cost to agree with actual
In-Reply-To: <87mym3iab9.fsf@oxford.xeocode.com>
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