Re: COPY FREEZE and setting PD_ALL_VISIBLE/visibility map bits

On Thu, Feb 21, 2019 at 3:05 PM Pavan Deolasee <pavan.deolasee@gmail.com> wrote:
>
> Hi,
>
> Jeff Janes raised an issue [1] about PD_ALL_VISIBLE not being set correctly while loading data via COPY FREEZE and
hadalso posted a draft patch. 
>
> I now have what I think is a more complete patch. I took a slightly different approach and instead of setting
PD_ALL_VISIBLEbit initially and then not clearing it during insertion, we now recheck the page for all-frozen,
all-visibletuples just before switching to a new page. This allows us to then also mark set the visibility map bit,
likewe do in vacuumlazy.c 

I might be missing something but why do we need to recheck whether
each pages is all-frozen after insertion? I wonder if we can set
all-frozen without checking all tuples again in this case.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center