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Re: bitmapscan test, no success, bs is not faster

From: Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Pavel Stehule <stehule(at)kix(dot)fsv(dot)cvut(dot)cz>,pgsql-hackers(at)postgresql(dot)org
Subject: Re: bitmapscan test, no success, bs is not faster
Date: 2005-04-26 16:35:24
Message-ID: Pine.GSO.4.62.0504262033510.4489@ra.sai.msu.su (view raw or flat)
Thread:
Lists: pgsql-hackers
I didn't vacuum tenk1 after loading into 8.02, so optimizer was optimistic
and used index. After vacuuming I got what's Tom get.
On Tue, 26 Apr 2005, Tom Lane wrote:

>
> In 8.0 this looks like
>
> regression=# explain analyze select * from tenk1 where hundred between 1 and 10 and thousand between 1 and 100;
>                                              QUERY PLAN
> -------------------------------------------------------------------------------------------------------
> Seq Scan on tenk1  (cost=0.00..558.00 rows=99 width=244) (actual time=0.171..69.189 rows=100 loops=1)
>   Filter: ((hundred >= 1) AND (hundred <= 10) AND (thousand >= 1) AND (thousand <= 100))
> Total runtime: 70.013 ms
> (3 rows)

 	Regards,
 		Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

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