Skip site navigation (1) Skip section navigation (2)

Re: HOT Patch - Ready for review

From: "Pavan Deolasee" <pavan(dot)deolasee(at)gmail(dot)com>
To: "Heikki Linnakangas" <heikki(at)enterprisedb(dot)com>
Cc: pgsql-patches(at)postgresql(dot)org
Subject: Re: HOT Patch - Ready for review
Date: 2007-04-20 07:57:26
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-patches
On 4/19/07, Heikki Linnakangas <heikki(at)enterprisedb(dot)com> wrote:
> What's the purpose of the "HeapScanHintPagePrune" mechanism in index
> builds? I lost track of the discussion on create index, is the it
> necessary for correctness?

Its not required strictly for correctness, but it helps us prune the
while index building. During index build, if we skip a tuple which is
RECENTLY_DEAD, existing transactions can not use the index for queries.
Pruning the HOT-chains reduces the possibility of finding such tuples
while building the index.

A comment in IndexBuildHeapScan explaining
> why it's done would be nice.

I would do that.

In any case a PG_TRY/CATCH block should be
> used to make sure it's turned off after an unsuccessful index build.

Oh thanks. Would do that too

I would wait for other review comments before submitting a fresh patch.
I hope thats ok.



In response to

pgsql-patches by date

Next:From: Zeugswetter Andreas ADI SDDate: 2007-04-20 08:16:15
Subject: Re: [HACKERS] Full page writes improvement, code update
Previous:From: Pavel StehuleDate: 2007-04-20 07:46:28
Subject: actualised forgotten Magnus's patch for plpgsql MOVE statement

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group