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

Re: testing HS/SR - 1 vs 2 performance

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Simon Riggs <simon(at)2ndquadrant(dot)com>
Cc: Erik Rijkers <er(at)xs4all(dot)nl>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: testing HS/SR - 1 vs 2 performance
Date: 2010-04-25 10:53:04
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers
On Sat, Apr 24, 2010 at 5:17 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>> Both Heikki and I objected to that patch.
> Please explain your objection, based upon the patch and my explanations.

Well, we objected to the locking.  Having reread the patch a few times
though, I think I'm starting to wrap my head around it so, I don't
know, maybe it's OK.  Have you tested grabbing the ProcArrayLock in
exclusive mode instead of having a separate spinlock, to see how that

>> And apparently it doesn't
>> fix the problem, either.  So, -1 from me.
> There is an issue observed in Erik's later tests, but my interpretation
> of the results so far is that the sorted array patch successfully
> removes the initially reported loss of performance.

Is it possible the remaining spikes are due to fights over the spinlock?


In response to


pgsql-hackers by date

Next:From: Robert HaasDate: 2010-04-25 12:46:17
Subject: Re: global temporary tables
Previous:From: Robert HaasDate: 2010-04-25 10:50:23
Subject: Re: global temporary tables

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