On Mon, Mar 27, 2017 at 04:29:56PM -0400, Robert Haas wrote:
> On Thu, Mar 23, 2017 at 2:47 PM, Pavan Deolasee
> <pavan.deola...@gmail.com> wrote:
> > It's quite hard to say that until we see many more benchmarks. As author of
> > the patch, I might have got repetitive with my benchmarks. But I've seen
> > over 50% improvement in TPS even without chain conversion (6 indexes on a 12
> > column table test).
> This seems quite mystifying.  What can account for such a large
> performance difference in such a pessimal scenario?  It seems to me
> that without chain conversion, WARM can only apply to each row once
> and therefore no sustained performance improvement should be possible
> -- unless rows are regularly being moved to new blocks, in which case
> those updates would "reset" the ability to again perform an update.
> However, one would hope that most updates get done within a single
> block, so that the row-moves-to-new-block case wouldn't happen very
> often.
> I'm perplexed.

Yes, I asked the same question in this email:


  Bruce Momjian  <br...@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +

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