Re: Surprising dead_tuple_count from pgstattuple

From: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
To: Gordon Shannon <gordo169(at)gmail(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Surprising dead_tuple_count from pgstattuple
Date: 2010-08-07 07:37:58
Message-ID: 4C5D0D56.9000602@enterprisedb.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On 07/08/10 07:43, Gordon Shannon wrote:
> Regarding HOT prune, I never did any updates, so I think there couldn't be
> any HOT tuples. Or does HOT prune do more than that?

Yes, HOT will also prune away DELETEd tuples. It will leave behind a
dead line pointer, so it won't stop the table from growing if you
repeatedly delete and insert, but it will slow it down significantly.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Boxuan Zhai 2010-08-07 07:58:13 Re: MERGE Specification
Previous Message Pavel Stehule 2010-08-07 07:24:11 Re: Initial review of xslt with no limits patch