From: Chad Thompson <chad@weblinkservices.com>
To: Peter T. Brown <peter@memeticsystems.com>
To: pgsql-sql@postgresql.org
Subject: Re: making queries more effecient
Date: Fri, 1 Nov 2002 15:04:42 -0700
Message-ID: <033301c281f2$aed1f7e0$32021aac@chad> (raw)
References: <1036189492.2013.16.camel@localhost.localdomain>
This should be all you need.
insert into VisitorPointer839 ("VisitorID")
select VisitorID
from ProgramEvent
Where ProgramID = 10
and Type = 0
group by VisitorID
You dont need order by because its not important the order it goes in the
database, just the order that it comes out.
I have found that group by works faster than distinct in some cases. You
may have to test it for your senario.
Thanks
Chad
----- Original Message -----
From: "Peter T. Brown" <peter@memeticsystems.com>
To: <pgsql-sql@postgresql.org>
Sent: Friday, November 01, 2002 3:24 PM
Subject: [SQL] making queries more effecient
> Hi. I have this query that I have been trying to reduce to a single
> statement, but haven't figured out how. Am I missing something?
>
> CREATE TEMP TABLE temp20561149207391 AS SELECT DISTINCT ON ("VisitorID")
> "VisitorID","Type" FROM "ProgramEvent" WHERE "ProgramID" = 10 ORDER BY
> "VisitorID","Created" DESC;INSERT INTO "VisitorPointer839" ("VisitorID")
> SELECT temp20561149207391."VisitorID" FROM temp20561149207391 WHERE
> temp20561149207391."Type" = 0
>
>
> Thanks
>
>
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To: pgsql-sql@postgresql.org
Cc: chad@weblinkservices.com, peter@memeticsystems.com
Subject: Re: making queries more effecient
In-Reply-To: <033301c281f2$aed1f7e0$32021aac@chad>
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