Re: Heap WARM Tuples - Design Draft

From: Claudio Freire <klaussfreire(at)gmail(dot)com>
To: Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com>
Cc: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Heap WARM Tuples - Design Draft
Date: 2016-08-05 01:18:25
Message-ID: CAGTBQpY_bJ-ARu0eqBSuN87y4v4xJkw2evMkXGZoKyTZ2Ou7zA@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Thu, Aug 4, 2016 at 7:59 AM, Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com> wrote:
> So marking the index would require us to mark both old and new index tuples
> as requiring re-check. That requires an additional index scan to locate the
> old row and then an additional write to force it to re-check, which is
> algorithmically O(NlogN) on table size.

So, basically, I'm saying this isn't really O(NlogN), it's O(N),
manifested in low-cardinality indexes.

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Michael Paquier 2016-08-05 01:51:57 Re: max_parallel_degree > 0 for 9.6 beta
Previous Message Bruce Momjian 2016-08-05 01:00:48 Re: Heap WARM Tuples - Design Draft