Re: removing PD_ALL_VISIBLE - Mailing list pgsql-hackers

From Josh Berkus
Subject Re: removing PD_ALL_VISIBLE
Date
Msg-id 51A8DDAC.3040109@agliodbs.com
Whole thread Raw
In response to Re: removing PD_ALL_VISIBLE  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: removing PD_ALL_VISIBLE  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
>> Isn't the visibility map already required for proper return results as
>> we use it for index-only scans.  I think the optimization-only ship has
>> sailed.
> 
> At the moment we can remove it without causing corruption. If we were to
> use it for freezing we couldn't anymore. So there's a difference - how
> big it is I am not sure.

Depends on your definition of corruption, really.

But yes, right now, the vismap can lose bits without causing any
corruption, and making all-frozen depend on it would eliminate that.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com



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