From: Tom Lane <tgl@sss.pgh.pa.us>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: PostgreSQL Performance <pgsql-performance@postgresql.org>
Subject: Re: join to view over custom aggregate seems like it should be faster
Date: Tue, 10 Apr 2007 13:03:06 -0400
Message-ID: <27416.1176224586@sss.pgh.pa.us> (raw)
In-Reply-To: <b42b73150704100559n3ccb9d89p1767a0fa94324375@mail.gmail.com>
References: <b42b73150704091205o668a084y1693520c974f3c6b@mail.gmail.com>
<10651.1176152866@sss.pgh.pa.us>
<b42b73150704091436g7fd1f903q1209218fc5eee88d@mail.gmail.com>
<b42b73150704100559n3ccb9d89p1767a0fa94324375@mail.gmail.com>
"Merlin Moncure" <mmoncure@gmail.com> writes:
> For some reason, I can't get the index to be used on the table sitting
> under a view during a join, even though it should be, or at least it
> seems....
Nope, that's not going to work, because the aggregate keeps the subquery
from being flattened into the upper query, which is what would have to
happen for a nestloop-with-inner-indexscan join to be considered.
AFAICS you've got to structure it so that the aggregation happens above
the join.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, mmoncure@gmail.com
Subject: Re: join to view over custom aggregate seems like it should be faster
In-Reply-To: <27416.1176224586@sss.pgh.pa.us>
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