Horton

Re: Re: Rethinking hint bits WAS: Protecting against unexpected zero-pages: proposal

Andrew Dunstan <andrew@dunslane.net>

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From: Andrew Dunstan <andrew@dunslane.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Greg Stark <gsstark@mit.edu>, Josh Berkus <josh@agliodbs.com>, pgsql-hackers@postgresql.org
Date: 2010-11-14T23:11:19Z
Lists: pgsql-hackers 

On 11/14/2010 05:15 PM, Tom Lane wrote:
> Josh is ignoring the proposal that is on the table and seems actually
> workable, which is to consult the visibility map during index-only
> scans.  For mostly-static tables this would save trips to the heap for
> very little extra I/O.  The hard part is to make the VM reliable, but
> that is not obviously harder than making separately-stored hint bits
> reliable.

I thought we had agreement in the past that this was the way we should 
proceed.

cheers

andrew