Re: [SQL] OFFSET impact on Performance???

From: "Spiegelberg, Greg" <gspiegelberg(at)cranel(dot)com>
To: 'Richard Huxton' <dev(at)archonet(dot)com>, Andrei Bintintan <klodoma(at)ar-sd(dot)net>
Cc: pgsql-sql(at)postgresql(dot)org, pgsql-performance(at)postgresql(dot)org
Subject: Re: [SQL] OFFSET impact on Performance???
Date: 2005-01-20 18:04:02
Message-ID: 387C22290D3FD71195D300508BF7DB5238B017@colmail01.cranel.local
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Isn't this a prime example of when to use a servlet or something similar
in function? It will create the cursor, maintain it, and fetch against
it for a particular page.

Greg

-----Original Message-----
From: Richard Huxton [mailto:dev(at)archonet(dot)com]
Sent: Thursday, January 20, 2005 10:21 AM
To: Andrei Bintintan
Cc: pgsql-sql(at)postgresql(dot)org; pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] [SQL] OFFSET impact on Performance???

Andrei Bintintan wrote:
>> If you're using this to provide "pages" of results, could you use a
>> cursor?
>
> What do you mean by that? Cursor?
>
> Yes I'm using this to provide "pages", but If I jump to the last pages
> it goes very slow.

DECLARE mycursor CURSOR FOR SELECT * FROM ...
FETCH FORWARD 10 IN mycursor;
CLOSE mycursor;

Repeated FETCHes would let you step through your results. That won't
work if you have a web-app making repeated connections.

If you've got a web-application then you'll probably want to insert the
results into a cache table for later use.

--
Richard Huxton
Archonet Ltd

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