From: | Matthew Wakeling <matthew(at)flymine(dot)org> |
---|---|
To: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: plpgsql arrays |
Date: | 2009-04-03 13:57:12 |
Message-ID: | alpine.DEB.2.00.0904031455210.21772@aragorn.flymine.org |
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Lists: | pgsql-performance |
On Fri, 3 Apr 2009, Robert Haas wrote:
> On Fri, Apr 3, 2009 at 9:32 AM, Matthew Wakeling <matthew(at)flymine(dot)org> wrote:
>> I'm writing a plpgsql function that effectively does a merge join on the
>> results of two queries.
> Why not just use SQL to do the join?
Because the merge condition is:
WHERE l1.start <= l2.end AND l2.start <= l1.end
and merge joins in postgres only currently cope with the case where the
merge condition is an equals relationship.
Oh, hang on, I think I saw something in the docs about what conditions can
be used in a merge...
Matthew
--
Let's say I go into a field and I hear "baa baa baa". Now, how do I work
out whether that was "baa" followed by "baa baa", or if it was "baa baa"
followed by "baa"?
- Computer Science Lecturer
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