From: Tom Lane <tgl@sss.pgh.pa.us>
To: Mikael Carneholm <Mikael.Carneholm@WirelessCar.com>
Cc: Pgsql performance <pgsql-performance@postgresql.org>
Subject: Re: Migration study, step 2: rewriting queries
Date: Sun, 16 Apr 2006 21:35:50 -0400
Message-ID: <20147.1145237750@sss.pgh.pa.us> (raw)
In-Reply-To: <7F10D26ECFA1FB458B89C5B4B0D72C2B3E3CF0@sesrv12.wirelesscar.com>
References: <7F10D26ECFA1FB458B89C5B4B0D72C2B3E3CF0@sesrv12.wirelesscar.com>
"Mikael Carneholm" <Mikael.Carneholm@WirelessCar.com> writes:
> ..and this last AND seems unnessecary, since the predicate on
> (driver_activity_type__id = 5) is included in each of the above
> conditions.
This should be fixed by the changes I made recently in choose_bitmap_and
--- it wasn't being aggressive about pruning overlapping AND conditions
when a sub-OR was involved. It's possible the new coding is *too*
aggressive, and will reject indexes that it'd be profitable to include;
but at least it won't make this particular mistake.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, Mikael.Carneholm@WirelessCar.com
Subject: Re: Migration study, step 2: rewriting queries
In-Reply-To: <20147.1145237750@sss.pgh.pa.us>
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