Re: testing HS/SR - 1 vs 2 performance
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Erik Rijkers <er@xs4all.nl>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, pgsql-hackers@postgresql.org
Date: 2010-04-25T16:51:58Z
Lists: pgsql-hackers
Simon Riggs <simon@2ndQuadrant.com> writes: > On Sun, 2010-04-25 at 11:50 -0400, Tom Lane wrote: >> This needs a redesign before it can be considered committable. I don't >> really care whether it makes things faster; it's too complicated and too >> poorly documented to be maintainable. > There are more than 60 lines of header comment explaining in detail how > this works, with a full algorithmic analysis. The remaining code is > commented to project standards, with easily more than 100 lines of > comments. If the comments were correct, I wouldn't be complaining. They're misleading or outright wrong on many points. In particular, I don't think you actually understand the weak-memory-ordering issue, because the comments about that are entirely wrong. I don't think they are adequate on other points either --- for example, I now understand why my complaint of a few minutes ago about KnownAssignedXidsValid is wrong, but the comments certainly didn't help me on that. regards, tom lane