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Re: getting estimated cost to agree with actual - Mailing list pgsql-performance

From Gregory Stark
Subject Re: getting estimated cost to agree with actual
Date
Msg-id 87mym3iab9.fsf@oxford.xeocode.com
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In response to Re: getting estimated cost to agree with actual  ("Scott Marlowe" <scott.marlowe@gmail.com>)
Responses Re: getting estimated cost to agree with actual  ("Scott Marlowe" <scott.marlowe@gmail.com>)
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"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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