Re: reducing the overhead of frequent table locks - now, with WIP patch

On Wed, Jun 8, 2011 at 6:02 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
>> Simon is right that we slipped the vxid patch into 8.3 when a Postgres
>> user I talked to at Linuxworld mentioned high vacuum freeze activity and
>> simple calculations showed the many read-only queries could cause high
>> xid usage.  Fortunately we already had a patch available and Tom applied
>> it during beta.  It was an existing patch that took on new urgency
>> during beta.
>
> Just to set the record straight on this ... the vxid patch went in on
> 2007-09-05:
> http://archives.postgresql.org/pgsql-committers/2007-09/msg00026.php
> which was a day shy of a month before we wrapped 8.3beta1:
> http://archives.postgresql.org/pgsql-committers/2007-10/msg00089.php
> so it was during alpha phase not beta.  And 8.3RC1 was stamped on
> 2008-01-03.  So Simon's assertion that this was "days before we produced
> a release candidate" is correct, if you take "days" as "4 months".

The patch went in slightly more than 6 months after feature freeze,
even though it was written by a summer student and did not even pass
review by the student's mentor (me).

The patch is invasive, involving core changes to the transaction
infrastructure and touching the more than 30 files.

It was a brilliant contribution from Florian.

I take it as an example of
* what you can do when you set your mind to it, given sufficient cause
and a good starting point
* how people can propose things of value to the community even at a late stage
* how I have respected the process at other times

--
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services