Re: a fast bloat measurement tool

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От Abhijit Menon-Sen
Тема Re: a fast bloat measurement tool
Дата
Msg-id 20140403043320.GB20877@toroid.org
обсуждение исходный текст
Ответ на Re: a fast bloat measurement tool (was Re: Measuring relation free space)  (Robert Haas <robertmhaas@gmail.com>)
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Дерево обсуждения 
At 2014-04-02 20:10:54 -0400, robertmhaas@gmail.com wrote:
>
> I think it might underestimate free space relative to tuples because
> the free space map isn't guaranteed to be completely correct.  But I
> guess you knew that already...

Yes, and tuple_len is already a slight overestimate (because it counts
the line pointer array as live tuple space for skipped pages). But for
the speedup it provides, I believe the result is still useful.

I'll mention the potential for free-space inaccuracy in the README.

-- Abhijit

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