Re: Group Commit

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <heikki@enterprisedb.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2007-04-09T22:52:19Z
Lists: pgsql-hackers
Heikki Linnakangas <heikki@enterprisedb.com> writes:
> I've been working on the patch to enhance our group commit behavior. The 
> patch is a dirty hack at the moment, but I'm settled on the algorithm 
> I'm going to use and I know the issues involved.

One question that just came to mind is whether Simon's no-commit-wait
patch doesn't fundamentally alter the context of discussion for this.
Aside from the prospect that people won't really care about group commit
if they can just use the periodic-WAL-sync approach, ISTM that one way
to get group commit is to just make everybody wait for the dedicated
WAL writer to write their commit record.  With a sufficiently short
delay between write/fsync attempts in the background process, won't
that net out at about the same place as a complicated group-commit
patch?

			regards, tom lane