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Re: Proposal for 9.1: WAL streaming from WAL buffers

Josh Berkus <josh@agliodbs.com>

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From: Josh Berkus <josh@agliodbs.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>, Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-06-11T22:16:26Z
Lists: pgsql-hackers 
> Well, we're already not waiting for fsync, which is the slowest part.
> If there's a performance problem, it may be because FADVISE_DONTNEED
> disables kernel buffering so that we're forced to actually read the data
> back from disk before sending it on down the wire.

Well, that's fairly direct to solve, no?  Just disable FADVISE_DONTNEED
if walsenders > 0.

-- 
                                  -- Josh Berkus
                                     PostgreSQL Experts Inc.
                                     http://www.pgexperts.com