Re: Dead Space Map for vacuum - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Dead Space Map for vacuum
Date
Msg-id 2589.1167407395@sss.pgh.pa.us
Whole thread Raw
In response to Re: Dead Space Map for vacuum  ("Simon Riggs" <simon@2ndquadrant.com>)
Responses Re: Dead Space Map for vacuum
List pgsql-hackers
"Simon Riggs" <simon@2ndquadrant.com> writes:
> I would suggest that we tracked whether a block has had 0, 1 or 1+
> updates/deletes against it. When a block has 1+ it can then be
> worthwhile to VACUUM it and to place it onto the FSM. Two dead tuples is
> really the minimum space worth reclaiming on any block.

How do you arrive at that conclusion?

Counterexample: table in which all tuples exceed half a page.
        regards, tom lane


pgsql-hackers by date:

Previous
From: Brian Hurt
Date:
Subject: Re: [PATCHES] [BUGS] BUG #2846: inconsistent and
Next
From: Stephen Frost
Date:
Subject: Re: TODO: GNU TLS