Re: Refactoring log_newpage

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Simon Riggs <simon(at)2ndQuadrant(dot)com>
Cc: Jim Nasby <jim(at)nasby(dot)net>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Refactoring log_newpage
Date: 2012-02-02 16:04:46
Message-ID: 24908.1328198686@sss.pgh.pa.us
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Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
> On Wed, Feb 1, 2012 at 10:42 PM, Jim Nasby <jim(at)nasby(dot)net> wrote:
>> But we already had RelFileNode; wouldn't that be enough to tell what rmgr was responsible for the new page? Can 2 different rmgrs write to the same file node?

> No, but which one? No way to tell unless you have full list of
> relfilenodes and check each one. So btree changes look like heap
> changes etc..

What I'm not following is why we should care. There are no cases at
present where this matters, and no proposed patches (that I know of)
that would make it matter. If an individual rmgr needs control of
what happens during a given operation, it wouldn't use XLOG_NEWPAGE
to represent the operation. End of problem. You haven't provided
any convincing argument why this needs to be changed globally.

regards, tom lane

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