Horton

Re: logical decoding and replication of sequences, take 2

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Amit Kapila <amit.kapila16@gmail.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Masahiko Sawada <sawada.mshk@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Date: 2023-12-06T05:42:35Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Migrate logical slots to the new node during an upgrade.

  2. Make test_decoding ddl.out shorter

  3. Fix snapshot handling in logicalmsg_decode

  4. doc: Adjust a few more references to "postmaster"

  5. Revert "Logical decoding of sequences"

On Sun, Dec 3, 2023 at 11:22 PM Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
>

> Some time ago I floated the idea of maybe "queuing" the sequence changes
> and only replay them on the next commit, somehow. But we did ran into
> problems with which snapshot to use, that I didn't know how to solve.
> Maybe we should try again. The idea is we'd queue the non-transactional
> changes somewhere (can't be in the transaction, because we must keep
> them even if it aborts), and then "inject" them into the next commit.
> That'd mean we wouldn't do the separate start/abort for each change.

Why can't we use the same concept of
SnapBuildDistributeNewCatalogSnapshot(), I mean we keep queuing the
non-transactional changes (have some base snapshot before the first
change), and whenever there is any catalog change, queue new snapshot
change also in the queue of the non-transactional sequence change so
that while sending it to downstream whenever it is necessary we will
change the historic snapshot?

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com