From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jim C. Nasby <jim@nasby.net>
Cc: Tobias Brox <tobias@nordicbet.com>
Cc: Chris Browne <cbbrowne@acm.org>
Cc: pgsql-performance@postgresql.org
Subject: Re: Simple join optimized badly?
Date: Mon, 09 Oct 2006 18:45:16 -0400
Message-ID: <9723.1160433916@sss.pgh.pa.us> (raw)
In-Reply-To: <20061009223030.GW72517@nasby.net>
References: <20061009213303.GA19144@oppetid.no>
<20061009223030.GW72517@nasby.net>
"Jim C. Nasby" <jim@nasby.net> writes:
> One of the big problems with doing set enable_...=off is that there's no
> way to embed that into something like a view, so you're almost forced
> into putting into the application code itself, which makes matters even
> worse. If you could hint this within a query (maybe even on a per-table
> level), you could at least encapsulate that into a view.
You've almost reinvented one of the points that was made in the last
go-round on the subject of hints, which is that keeping them out of the
application code is an important factor in making them manageable by a
DBA. Hints stored in a system catalog (and probably having the form of
"make this statistical assumption" rather than specifically "use that
plan") would avoid many of the negatives.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, jim@nasby.net, tobias@nordicbet.com, cbbrowne@acm.org
Subject: Re: Simple join optimized badly?
In-Reply-To: <9723.1160433916@sss.pgh.pa.us>
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