Re: Page Checksums + Double Writes

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>, Simon Riggs <simon@2ndquadrant.com>, alvherre@commandprompt.com, david@fetter.org, pgsql-hackers@postgresql.org
Date: 2011-12-23T17:42:42Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> An obvious problem is that, if the abort rate is significantly
> different from zero, and especially if the aborts are randomly mixed
> in with commits rather than clustered together in small portions of
> the XID space, the CLOG rollup data would become useless.

Yeah, I'm afraid that with N large enough to provide useful
acceleration, the cases where you'd actually get a win would be too thin
on the ground to make it worth the trouble.

			regards, tom lane