Re: testing HS/SR - 1 vs 2 performance

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

Cc: Simon Riggs <simon@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Erik Rijkers <er@xs4all.nl>, pgsql-hackers@postgresql.org

Date: 2010-04-21T14:11:00Z

Lists: pgsql-hackers

On Wed, Apr 21, 2010 at 8:20 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> The locking seems overly complex to me.

I tend to agree.

! 	/*
! 	 * Callers must hold either ProcArrayLock in Exclusive mode or
! 	 * ProcArrayLock in Shared mode *and* known_assigned_xids_lck
! 	 * to update these values.
! 	 */

I'm not convinced that this is either (a) correct or (b) performant.

...Robert