From: | David Wheeler <david(at)wheeler(dot)net> |
---|---|
To: | Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> |
Cc: | <sfpug(at)postgresql(dot)org> |
Subject: | Re: Offset |
Date: | 2003-08-28 19:47:49 |
Message-ID: | 8108D4EF-D990-11D7-9D24-0003931A964A@wheeler.net |
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Thread: | |
Lists: | sfpug |
On Thursday, August 28, 2003, at 11:58 AM, Stephan Szabo wrote:
>> It calls them "derived tables", which makes sense to me. Couldn't see
>
> One question is whether or not they can have limit clauses applied to
> them in the query expression, but they probably can.
Yeah, and they use the same keywords, which I applaud. Not that it
matters, since Bricolage hasn't been ported yet.
> Looks like 7.2 supports queries of that form from trying against our
> unused 7.2 server here.
Oh, good. I have no trouble bumping the requirement up to 7.2. 7.1 is
ancient history already.
> Performance-wise it should be pretty reasonable since the query plan
> for that section basically becomes
> Subquery Scan
> Limit
> <Normal Scan>
> where the limit and subquery scan should be nearly free. And, it save
> you
> from having to join rows that you're not actually using.
Excellent. Many thanks again, Stephan.
Regards,
David
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