Re: limiting hint bit I/O
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-hackers@postgresql.org
Date: 2011-01-14T18:06:03Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes: > On Fri, Jan 14, 2011 at 12:47 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: >> Moreover this whole business of not treating hint-bit setting as >> a page-dirtying operation is completely experimental/unproven IMO, so it >> would be better to keep the patch footprint as small as possible. > I have some concerns about that proposal, but it might be the right > way to go. Before we get too far off into the weeds, though, let's > back up and talk about something more fundamental: this seems to be > speeding up the first run by 6x at the expense of slowing down many > subsequent runs by 10-15%. Does that make this whole idea dead on > arrival? Well, it reinforces my opinion that it's experimental ;-). But "first run" of what, exactly? And are you sure you're taking a wholistic view of the costs/benefits? regards, tom lane