Horton

Re: COPY FREEZE and setting PD_ALL_VISIBLE/visibility map bits

Masahiko Sawada <sawada.mshk@gmail.com>

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From: Masahiko Sawada <sawada.mshk@gmail.com>
To: Pavan Deolasee <pavan.deolasee@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>, Jeff Janes <jeff.janes@gmail.com>, Simon Riggs <simon@2ndquadrant.com>
Date: 2019-03-11T08:03:57Z
Lists: pgsql-hackers 
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 had also 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_VISIBLE bit initially and then not clearing it during insertion, we now recheck the page for all-frozen, all-visible tuples just before switching to a new page. This allows us to then also mark set the visibility map bit, like we 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

Commits

  1. Fix COPY FREEZE with CLOBBER_CACHE_ALWAYS

  2. Set PD_ALL_VISIBLE and visibility map bits in COPY FREEZE

  3. docs: client certificates are always sent to the server

  4. Mark commit and abort WAL records with XLR_SPECIAL_REL_UPDATE.

  5. docs: land height is "elevation", not "altitude"

  6. Improve the internal implementation of ereport().