Re: 9.2.1 & index-only scans : abnormal heap fetches after VACUUM FULL

On Thu, Nov 28, 2013 at 05:38:05PM -0500, Bruce Momjian wrote:
> > I wonder if we ought to mark each page as all-visible in
> > raw_heap_insert() when we first initialize it, and then clear the flag
> > when we come across a tuple that isn't all-visible. We could try to
> > set hint bits on the tuple before placing it on the page, too, though
> > I'm not sure of the details.
>
> I went with the per-page approach because I wanted to re-use the vacuum
> lazy function. Is there some other code that does this already? I am
> trying to avoid yet-another set of routines that would need to be
> maintained or could be buggy. This hit bit setting is tricky.
>
> And thanks much for the review!

So, should I put this in the next commit fest? I still have an unknown
about the buffer number to use here:

! /* XXX use 0 or real offset? */
! ItemPointerSet(&(tuple.t_self), BufferIsValid(buf) ?
! BufferGetBlockNumber(buf) : 0, offnum);

Is everyone else OK with this approach? Updated patch attached.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ Everyone has their own god. +