Re: [PoC] pgstattuple2: block sampling to reduce physical read - Mailing list pgsql-hackers

From Jaime Casanova
Subject Re: [PoC] pgstattuple2: block sampling to reduce physical read
Date
Msg-id CAJKUy5g1Kh8Urc1nSUDOyTG_b3opBVjp=7_ZBjgiGdPutee-jQ@mail.gmail.com
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In response to Re: [PoC] pgstattuple2: block sampling to reduce physical read  (Mark Kirkwood <mark.kirkwood@catalyst.net.nz>)
Responses Re: [PoC] pgstattuple2: block sampling to reduce physical read
Re: [PoC] pgstattuple2: block sampling to reduce physical read
List pgsql-hackers
On Thu, Oct 10, 2013 at 5:32 PM, Mark Kirkwood
<mark.kirkwood@catalyst.net.nz> wrote:
>
> Quietly replying to myself - looking at the code the sampler does 3000
> random page reads...

FWIW, something that bothers me is that there is 3000 random page
reads... i mean, why 3000? how do you get that number as absolute for
good accuracy in every relation? why not a percentage, maybe an
argument to the function?

also the name pgstattuple2, doesn't convince me... maybe you can use
pgstattuple() if you use a second argument (percentage of the sample)
to overload the function

--
Jaime Casanova         www.2ndQuadrant.com
Professional PostgreSQL: Soporte 24x7 y capacitación
Phone: +593 4 5107566         Cell: +593 987171157



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