Re: 7.4beta2 vs 7.3.3 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: 7.4beta2 vs 7.3.3
Date
Msg-id 7535.1063939208@sss.pgh.pa.us
Whole thread Raw
In response to Re: 7.4beta2 vs 7.3.3  (Gaetano Mendola <mendola@bigfoot.com>)
Responses Re: 7.4beta2 vs 7.3.3  (Gaetano Mendola <mendola@bigfoot.com>)
List pgsql-hackers
Gaetano Mendola <mendola@bigfoot.com> writes:
> Tom Lane wrote:
>> Hm, it sure looks to be exactly the same plan.  The performance
>> difference seems to be just that the seqscans are faster.  I surmise
>> that in the 7.3 database you had a lot of dead rows, or at least a lot
>> of free space.  Possibly you need to vacuum more often to keep down the
>> amount of junk in the tables.

> The two databases were created from scratch and the first
> operation on it ( after a vacuum analyze ) was just that query.

Y'know, I'd love to think that 7.4 is 2x faster than 7.3 on seqscanning,
but I just can't believe that.  We didn't do anything that could account
for such a speedup.  So there's got to be some inconsistency in your
test conditions.
        regards, tom lane


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