From: Richard Huxton <dev@archonet.com>
To: ta145@yahoo.com
To: pgsql-general@postgresql.org
To: pgsql-php@postgresql.org
To: pgsql-sql@postgresql.org
Subject: Re: looking to speed up SELECT ... LEFT JOIN query
Date: Thu, 8 Aug 2002 15:24:17 +0100
Message-ID: <200208081524.17392.dev@archonet.com> (raw)
In-Reply-To: <1b23bd38.0208062103.3ec45a2b@posting.google.com>
References: <1b23bd38.0208062103.3ec45a2b@posting.google.com>
On Wednesday 07 Aug 2002 6:03 am, Trey Ackerman wrote:
> Hi,
>
> I have a working SELECT statement using LEFT JOIN but I'm hoping
> someone can suggest something that might be a bit quicker (currently 3
> seconds for result).
>
> SELECT * FROM ((table1 LEFT JOIN table2 USING (custno)) AS j1
> LEFT JOIN table3 USING (custno)) AS j2
> LEFT JOIN table4 USING (custno)
> WHERE custno='$custno';
>
> The primary table is table1, the key for all tables is 'custno'. I
> need the LEFT JOIN because any one or all of the other tables (table2,
> table3, table4) might not have corresponding data.
We'll need to see the output of an EXPLAIN / EXPLAIN ANALYSE - also could you
join the tables in a different order, smallest first?
- Richard Huxton
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To: pgsql-sql@postgresql.org
Cc: dev@archonet.com, ta145@yahoo.com, pgsql-general@postgresql.org, pgsql-php@postgresql.org
Subject: Re: looking to speed up SELECT ... LEFT JOIN query
In-Reply-To: <200208081524.17392.dev@archonet.com>
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