Re: Re: patch submission: truncate trailing nulls from heap rows to reduce the size of the null bitmap [Review]
Amit Kapila <amit.kapila@huawei.com>
From: Amit Kapila <amit.kapila@huawei.com>
To: "'Simon Riggs'" <simon@2ndQuadrant.com>
Cc: "'Kevin Grittner'" <kgrittn@mail.com>, <robertmhaas@gmail.com>, <josh@agliodbs.com>, <pgsql-hackers@postgresql.org>
Date: 2013-01-09T12:06:14Z
Lists: pgsql-hackers
On Wednesday, January 09, 2013 4:52 PM Simon Riggs wrote: > On 24 December 2012 16:57, Amit Kapila <amit.kapila@huawei.com> wrote: > > > Performance: Average of 3 runs of pgbench in tps > > 9.3devel | with trailing null patch > > ----------+-------------------------- > > 578.9872 | 573.4980 > > On balance, it would seem optimizing for this special case would > affect everybody negatively; not much, but enough. Which means we > should rekect this patch. > > Do you have a reason why a different view might be taken? I have tried to dig why this gap is coming. I have observed that there is very less change in normal path. I wanted to give it some more time to exactly find if something can be done to avoid performance dip in normal execution. Right now I am busy in certain other work. But definitely in coming week or so, I shall spare time to work on it again. With Regards, Amit Kapila.
Commits
-
Don't assume that a tuple's header size is unchanged during toasting.
- 039680affb1b 9.2.0 cited