Re: New vacuum option to do only freezing - Mailing list pgsql-hackers

From Robert Haas
Subject Re: New vacuum option to do only freezing
Date
Msg-id CA+Tgmoaw=621_-0Dc4=6S8i9p3vFPYVRtUXg33Hw-a160KRScg@mail.gmail.com
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In response to Re: New vacuum option to do only freezing  (Masahiko Sawada <sawada.mshk@gmail.com>)
Responses Re: New vacuum option to do only freezing  (Masahiko Sawada <sawada.mshk@gmail.com>)
List 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


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