Re: Combining two bitmap scans out performs a single regular index scan?

From: Mark Mielke <mark(at)mark(dot)mielke(dot)cc>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Combining two bitmap scans out performs a single regular index scan?
Date: 2007-12-08 22:07:25
Message-ID: 475B159D.8000203@mark.mielke.cc
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Tom Lane wrote:
> Mark Mielke <mark(at)mark(dot)mielke(dot)cc> writes:
>
>> To find records after a certain time, I must do one of:
>> select * from icpric where audtdate > ? or (audtdate = ? and
>> audttime > ?)
>>
> In recent releases (at least 8.2, don't remember about 8.1), a row
> comparison is what you want:
>
> WHERE (auddate, adttime) > (?, ?)
>
Cool! That's the ticket. :-)

I guess it would be unnecessary to translate the other two queries into
this one for the purpose of planning, eh? :-)

Cheers,
mark

--
Mark Mielke <mark(at)mielke(dot)cc>

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