Re: Help with tuning this query

From: Ragnar Hafstað
Subject: Re: Help with tuning this query
Date: ,
Msg-id: 1109787227.31084.12.camel@localhost.localdomain
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In response to: Help with tuning this query  ("Ken Egervari")
List: pgsql-performance

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Help with tuning this query  ("Ken Egervari", )
 Re: Help with tuning this query  (Richard Huxton, )
  Re: Help with tuning this query  (Bricklen Anderson, )
   Re: Help with tuning this query  (Bruce Momjian, )
 Re: Help with tuning this query  (John Arbash Meinel, )
 Re: Help with tuning this query  ("Ken Egervari", )
  Re: Help with tuning this query  (John Arbash Meinel, )
 Re: Help with tuning this query  (Ragnar Hafstað, )
 Re: Help with tuning this query  ("Ken Egervari", )
  Re: Help with tuning this query  (Ragnar Hafstað, )
 Re: Help with tuning this query  ("Ken Egervari", )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
  Re: Help with tuning this query (with explain analyze finally)  (Tom Lane, )
   Re: Help with tuning this query (with explain analyze finally)  (John A Meinel, )
  Re: Help with tuning this query (with explain analyze finally)  (Josh Berkus, )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
  Re: Help with tuning this query (with explain analyze finally)  (Tom Lane, )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
 Re: Help with tuning this query (more musings)  ("Ken Egervari", )
  Re: Help with tuning this query (more musings)  (John A Meinel, )
 Re: Help with tuning this query (Some musings)  ("Ken Egervari", )
 Re: Help with tuning this query  (Mark Kirkwood, )
 Re: Help with tuning this query  (Josh Berkus, )
 Re: Help with tuning this query (more musings)  ("Ken Egervari", )
  Re: Help with tuning this query (more musings)  (Richard Huxton, )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
  Re: Help with tuning this query (with explain analyze finally)  (Josh Berkus, )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
  Re: Help with tuning this query (with explain analyze finally)  (John Arbash Meinel, )
  Re: Help with tuning this query (with explain analyze finally)  (Josh Berkus, )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken Egervari", )
  Re: Help with tuning this query (with explain analyze finally)  (Richard Huxton, )
  Re: Help with tuning this query (with explain analyze finally)  (John Arbash Meinel, )
 Re: Help with tuning this query (with explain analyze finally)  ("Ken", )
  Re: Help with tuning this query (with explain analyze finally)  (John Arbash Meinel, )
   Re: Help with tuning this query (with explain analyze finally)  (John A Meinel, )

On Wed, 2005-03-02 at 01:51 -0500, Ken Egervari wrote:
>
> select s.*
> from shipment s
>     inner join carrier_code cc on s.carrier_code_id = cc.id
>     inner join carrier c on cc.carrier_id = c.id
>     inner join carrier_to_person ctp on ctp.carrier_id = c.id
>     inner join person p on p.id = ctp.person_id
>     inner join shipment_status cs on s.current_status_id = cs.id
>     inner join release_code rc on cs.release_code_id = rc.id
>     left join shipment_status ss on ss.shipment_id = s.id
> where
>     p.id = :personId and
>     s.is_purged = false and
>     rc.number = '9' and
>     cs is not null and
>     cs.date >= current_date - 31
> order by cs.date desc
> ...
> shipment contains 40,000 rows
> shipment_status contains 80,000 rows

I may be missing something, but it looks like the second join
on shipment_status (the left join) is not adding anything to your
results, except more work. ss is not used for output, nor in the where
clause, so what is its purpose ?

if cs.date has an upper limit, it might be helpful to change the
condition to a BETWEEN

in any case, i would think you might need an index on
  shipment(carrier_code_id)
  shipment(current_status_id)
  shipment_status(id)

gnari





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From: John A Meinel
Date:
Subject: Re: Help with tuning this query (with explain analyze finally)
From: "Ken Egervari"
Date:
Subject: Re: Help with tuning this query (with explain analyze finally)