Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Michael Paquier <michael@paquier.xyz>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-01-23T03:37:23Z
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. Tighten the concurrent abort check during decoding.

  2. Improve hash_create()'s API for some added robustness.

  3. Use HASH_BLOBS for xidhash.

  4. Fix initialization of RelationSyncEntry for streaming transactions.

  5. Remove unused function declaration in logicalproto.h.

  6. Add additional tests to test streaming of in-progress transactions.

  7. Fix inline marking introduced in commit 464824323e.

  8. Add support for streaming to built-in logical replication.

  9. Fix the SharedFileSetUnregister API.

  10. Fix comment in procarray.c

  11. Suppress compiler warning in non-cassert builds.

  12. Extend the BufFile interface.

  13. Mark a few logical decoding related variables with PGDLLIMPORT.

  14. Implement streaming mode in ReorderBuffer.

  15. Extend the logical decoding output plugin API with stream methods.

  16. WAL Log invalidations at command end with wal_level=logical.

  17. Immediately WAL-log subtransaction and top-level XID association.

  18. Allow logical replication to transfer data in binary format.

  19. Only superuser can set sslcert/sslkey in postgres_fdw user mappings

  20. Track statistics for spilling of changes from ReorderBuffer.

  21. Add logical_decoding_work_mem to limit ReorderBuffer memory usage.

  22. logical decoding: process ASSIGNMENT during snapshot build

  23. Emit invalidations to standby for transactions without xid.

On Wed, Jan 22, 2020 at 10:07 PM Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
>
> I looked at this patchset and it seemed natural to apply 0008 next
> (adding work_mem to subscriptions).
>

I am not so sure whether we need this patch as the exact scenario
where it can help is not very clear to me and neither did anyone
explained.  I have raised this concern earlier as well [1].  The point
is that 'logical_decoding_work_mem' applies to the entire
ReorderBuffer in the publisher's side and how will a parameter from a
particular subscription help in that?

[1] - https://www.postgresql.org/message-id/CAA4eK1J%2B3kab6RSZrgj0YiQV1r%2BH3FWVaNjKhWvpEe5-bpZiBw%40mail.gmail.com

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com