Re: 9.2.1 & index-only scans : abnormal heap fetches after VACUUM FULL - Mailing list pgsql-hackers

On Thursday, January 10, 2013 6:09 AM Josh Berkus wrote:
> On 01/09/2013 03:07 PM, Bruce Momjian wrote:
> > How do we want to handle the case where VACUUM FULL clears the
> > visibility map, causing loss of index-only scans?
> >
> >     http://archives.postgresql.org/pgsql-performance/2012-
> 11/msg00317.php
> >
> > Do we document this behavior or add a TODO item?
> >
>
> Both?
>
> Surely VACUUM FULL should rebuild the visibility map, and make tuples
> in
> the new relation all-visible, no?

I think it cannot made all visible.
How about if any transaction in SSI mode is started before Vacuum Full, should it see all tuples.

With Regards,
Amit Kapila.