From: Andrei Bintintan <klodoma@ar-sd.net>
To: alex@neteconomist.com
To: Greg Stark <gsstark@mit.edu>
Cc: Richard Huxton <dev@archonet.com>
Cc: pgsql-sql@postgresql.org
Cc: pgsql-performance@postgresql.org
Subject: Re: [SQL] OFFSET impact on Performance???
Date: Wed, 26 Jan 2005 12:11:49 +0200
Message-ID: <015a01c5038f$73a70720$0b00a8c0@forge> (raw)
References: <019f01c4fee1$1b58d600$0b00a8c0@forge>
<41EF9FD3.5020400@archonet.com>
<020d01c4fef6$595bb9d0$0b00a8c0@forge>
<41EFCC5B.5010302@archonet.com>
<33c6269f05012008391490448b@mail.gmail.com>
<87y8eh1hy9.fsf@stark.xeocode.com>
The problems still stays open.
The thing is that I have about 20 - 30 clients that are using that SQL query
where the offset and limit are involved. So, I cannot create a temp table,
because that means that I'll have to make a temp table for each session...
which is a very bad ideea. Cursors somehow the same. In my application the
Where conditions can be very different for each user(session) apart.
The only solution that I see in the moment is to work at the query, or to
write a more complex where function to limit the results output. So no
replace for Offset/Limit.
Best regards,
Andy.
----- Original Message -----
From: "Greg Stark" <gsstark@mit.edu>
To: <alex@neteconomist.com>
Cc: "Richard Huxton" <dev@archonet.com>; "Andrei Bintintan"
<klodoma@ar-sd.net>; <pgsql-sql@postgresql.org>;
<pgsql-performance@postgresql.org>
Sent: Tuesday, January 25, 2005 8:28 PM
Subject: Re: [PERFORM] [SQL] OFFSET impact on Performance???
>
> Alex Turner <armtuk@gmail.com> writes:
>
>> I am also very interesting in this very question.. Is there any way to
>> declare a persistant cursor that remains open between pg sessions?
>> This would be better than a temp table because you would not have to
>> do the initial select and insert into a fresh table and incur those IO
>> costs, which are often very heavy, and the reason why one would want
>> to use a cursor.
>
> TANSTAAFL. How would such a persistent cursor be implemented if not by
> building a temporary table somewhere behind the scenes?
>
> There could be some advantage if the data were stored in a temporary table
> marked as not having to be WAL logged. Instead it could be automatically
> cleared on every database start.
>
> --
> greg
>
>
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Subject: Re: [SQL] OFFSET impact on Performance???
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