Yes, the additional bitmap could certainly explain the increase.
Thanks,
Mike
-----Original Message-----
From: Justin Pryzby [mailto:pryzby@telsasoft.com]
Sent: Friday, December 06, 2019 6:29 PM
To: Mike Schanne
Cc: pgsql-performance@postgresql.org
Subject: Re: unexpected result for wastedbytes query after vacuum full
On Fri, Dec 06, 2019 at 05:18:20PM +0000, Mike Schanne wrote:
> Hi all,
>
> This question is somewhat related to my previous question:
> https://www.postgresql.org/message-id/0871fcf35ceb4caa8a2204ca9c38e330%40USEPRDEX1.corp.kns.com
>
> I was attempting to measure the benefit of doing a VACUUM FULL on my database. I was using the query found here:
> https://wiki.postgresql.org/wiki/Show_database_bloat
>
> However, I got an unexpected result in that the "wastedbytes" value actually increased for some tables after doing
thevacuum.
> I was wondering if the fact that we use a json column could be interfering with the wastedbytes calculation. Can
anyoneexplain how wastedbytes could increase from a vacuum?
Is it due to dropped columns, like Tom explained here ?
https://www.postgresql.org/message-id/18375.1520723971%40sss.pgh.pa.us
________________________________
This email is non-binding, is subject to contract, and neither Kulicke and Soffa Industries, Inc. nor its subsidiaries
(eachand collectively “K&S”) shall have any obligation to you to consummate the transactions herein or to enter into
anyagreement, other than in accordance with the terms and conditions of a definitive agreement if and when negotiated,
finalizedand executed between the parties. This email and all its contents are protected by International and United
Statescopyright laws. Any reproduction or use of all or any part of this email without the express written consent of
K&Sis prohibited.
