Horton
Menu

Re: [COMMITTERS] pgsql: Augment WAL records for btree delete with GetOldestXmin() to

Greg Stark <gsstark@mit.edu>

View thread
From: Greg Stark <gsstark@mit.edu>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>, pgsql-hackers@postgresql.org
Date: 2010-03-27T19:15:37Z
Lists: pgsql-hackers 
On Sat, Mar 27, 2010 at 10:10 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> It appears that in practice many of the index items point to heap items
> that are LP_DEAD. So for the purposes of accessing a heap tuple's xmin,
> then we're both right. To the current purpose the tuple has been
> removed, though you are also right: its stub remains.

If we're pruning an index entry to a heap tuple that has been HOT
pruned wouldn't the HOT pruning record have already conflicted with
any queries that could see  it?


-- 
greg