Re: Multiple Order By Criteria - Mailing list pgsql-performance

From J@Planeti.Biz
Subject Re: Multiple Order By Criteria
Date
Msg-id 05d801c61bb5$6c8824d0$681e140a@fatchubby
Whole thread Raw
In response to Multiple Order By Criteria  (J@Planeti.Biz)
Responses Re: Multiple Order By Criteria  (Fredrick O Jackson <fred@arkansaswebs.com>)
List pgsql-performance
I created the index, in order. Did a vacuum analyze on the table and my
explain still says:

Limit  (cost=229610.78..229611.03 rows=100 width=717)
  ->  Sort  (cost=229610.78..230132.37 rows=208636 width=717)
        Sort Key: receipt, carrier_id, batchnum, encounternum, encounter_id
        ->  Seq Scan on detail_summary ds  (cost=0.00..22647.13 rows=208636
width=717)
              Filter: (receipt >= '2004-03-22'::date)


So, for fun I did
set enable_seqscan to off

But that didn't help. For some reason, the sort wants to do a seq scan and
not use my super new index.

Am I doing something wrong ?

----- Original Message -----
From: "Josh Berkus" <josh@agliodbs.com>
To: <pgsql-performance@postgresql.org>
Cc: <J@planeti.biz>
Sent: Tuesday, January 17, 2006 5:25 PM
Subject: Re: [PERFORM] Multiple Order By Criteria


> J,
>
>> I have an index built for each of these columns in my order by clause.
>> This query takes an unacceptable amount of time to execute. Here are the
>> results of the explain:
>
> You need a single index which has all five columns, in order.
>

> --
> --Josh
>
> Josh Berkus
> Aglio Database Solutions
> San Francisco
>
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