Horton

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

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Erik Rijkers <er@xs4all.nl>, Kuntal Ghosh <kuntalghosh.2007@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-06-10T11:31:50Z
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, Jun 10, 2020 at 4:00 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Wed, Jun 10, 2020 at 2:30 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
> >
> > Currently, I am done with a working prototype of using the BufFile
> > infrastructure for the tempfile.  Meanwhile, I want to discuss a few
> > interface changes required for the BufFIle infrastructure.
> >
> > 1. Support read-write mode for "BufFileOpenShared",  Basically, in
> > workers we will be opening the xid's changes and subxact files per
> > stream, so we need an RW mode even in the open.  I have passed a flag
> > for the same.
> >
>
> Generally file open APIs have mode as a parameter to indicate
> read_only or read_write.  Using flag here seems a bit odd to me.

Let me think about it, we can try to pass the mode.

> > 2. Files should not be closed at the end of the transaction:
> > Currently, files opened with BufFileCreateShared/BufFileOpenShared are
> > registered to be closed on EOXACT.  Basically, we need to open the
> > changes file on the stream start and keep it open until stream stop,
> > so we can not afford to get it closed on the EOXACT.  I have added a
> > flag for the same.
> >
>
> But where do we end the transaction before the stream stop which can
> lead to closure of this file?

Currently, I am keeping the transaction only while creating/opening
the files and closing immediately after that,  maybe we can keep the
transaction until stream stop, then we can avoid this changes,  and we
can also avoid creating extra resource owner?  What is your thought on
this?

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