Horton

Re: New vacuum option to do only freezing

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: "Bossart, Nathan" <bossartn@amazon.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2019-01-11T18:27:43Z
Lists: pgsql-hackers 
On Fri, Jan 11, 2019 at 1:14 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> Attached the updated patch. Please review it.

I'm quite confused by this patch.  It seems to me that the easiest way
to implement this patch would be to (1) make lazy_space_alloc take the
maxtuples = MaxHeapTuplesPerPage branch when the new option is
specified, and then (2) forget about them after each page i.e.

        if (nindexes == 0 &&
            vacrelstats->num_dead_tuples > 0)
        {
...
        }
        else if (skipping index cleanup)
            vacrelstats->num_dead_tuples = 0;

I don't see why it should touch the logic inside lazy_vacuum_page() or
the decision about whether to truncate.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Add toast-level reloption for vacuum_index_cleanup

  2. heap_prepare_freeze_tuple: Simplify coding

  3. Fix missing word.

  4. Allow VACUUM to be run with index cleanup disabled.

  5. Don't mark pages all-visible spuriously