Message-ID: <4EC9CCC6.4030906@lab.ntt.co.jp>
Date: Mon, 21 Nov 2011 13:00:06 +0900
From: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>
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To: Robert Haas <robertmhaas@gmail.com>
CC: Shigeru Hanada <shigeru.hanada@gmail.com>, pgsql-hackers@postgresql.org
Subject: Re: WIP: Collecting statistics on CSV file data
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(2011/11/19 0:54), Robert Haas wrote:
> 2011/11/18 Shigeru Hanada<shigeru.hanada@gmail.com>:
>> - I couldn't see the reason why file_fdw sets ctid of sample tuples,
>> though I guess it's for Vitter's random sampling algorithm.  If every
>> FDW must set valid ctid to sample tuples, it should be mentioned in
>> document of AnalyzeForeignTable.  Exporting some functions from
>> analyze.c relates this issue?
>
> If every FDW must set valid ctid to sample tuples, it should be fixed
> so that they don't have to, I would think.

It's for neither Vitter's algorithm nor exporting functions from 
analyze.c.  It's for "foreign index scan" on CSV file data that I plan 
to propose in the next CF.  So, it is meaningless for now.  I'm sorry. 
I will fix it at the next version of the patch so that they don't have to.

Best regards,
Etsuro Fujita