Horton

Re: Decoding speculative insert with toast leaks memory

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Petr Jelinek <petr.jelinek@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Tomas Vondra <tomas.vondra@enterprisedb.com>
Date: 2021-06-01T04:23:40Z
Lists: pgsql-hackers 
On Mon, May 31, 2021 at 8:12 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Mon, May 31, 2021 at 6:32 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
> > I missed to do the test for streaming.  I will to that tomorrow and reply back.
>
> For streaming transactions this issue is not there. Because this
> problem will only occur if the last change is *SPEC INSERT * and after
> that there is no other UPDATE/INSERT change because on that change we
> are resetting the toast table.  Now, if the transaction has only *SPEC
> INSERT* without SPEC CONFIRM or any other INSERT/UPDATE then we will
> not stream it.  And if we get any next INSERT/UPDATE then only we can
> select this for stream but in that case toast will be reset.  So as of
> today for streaming mode we don't have this problem.
>

What if the next change is a different SPEC_INSERT
(REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT)? I think in that case we
will stream but won't free the toast memory.

-- 
With Regards,
Amit Kapila.

Commits

  1. Fix ABI break introduced by commit 4daa140a2f.

  2. Fix valgrind issue in pgoutput.c.

  3. Fix decoding of speculative aborts.

  4. pgoutput: Fix memory leak due to RelationSyncEntry.map.

  5. Fix initialization of RelationSyncEntry for streaming transactions.

  6. Implement streaming mode in ReorderBuffer.