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: 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: 2020-05-26T09:13:59Z
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 Tue, May 26, 2020 at 10:27 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Fri, May 22, 2020 at 6:21 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
> > On Mon, May 18, 2020 at 5:57 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > >
> > >
> > > Few comments on v20-0010-Bugfix-handling-of-incomplete-toast-tuple
> > > 1.
> > > + /*
> > > + * If this is a toast insert then set the corresponding bit.  Otherwise, if
> > > + * we have toast insert bit set and this is insert/update then clear the
> > > + * bit.
> > > + */
> > > + if (toast_insert)
> > > + toptxn->txn_flags |= RBTXN_HAS_TOAST_INSERT;
> > > + else if (rbtxn_has_toast_insert(txn) &&
> > > + ChangeIsInsertOrUpdate(change->action))
> > > + {
> > >
> > > Here, it might better to add a comment on why we expect only
> > > Insert/Update?  Also, it might be better that we add an assert for
> > > other operations.
> >
> > I have added comments that why on Insert/Update we clean the flag.
> > But I don't think we only expect insert/update,  we might get the
> > toast delete right? because in toast update we will do toast delete +
> > toast insert.  So when we get toast delete we just don't want to do
> > anything.
> >
>
> Okay, that makes sense.
>
> > >
> > > 2.
> > > @@ -1865,8 +1920,8 @@ ReorderBufferProcessTXN(ReorderBuffer *rb,
> > > ReorderBufferTXN *txn,
> > >   * disk.
> > >   */
> > >   dlist_delete(&change->node);
> > > - ReorderBufferToastAppendChunk(rb, txn, relation,
> > > -   change);
> > > + ReorderBufferToastAppendChunk(rb, txn, relation,
> > > +   change);
> > >   }
> > >
> > > This seems to be a spurious change.
> >
> > Done
> >
> > 2. There is a bug fix in handling the stream abort in 0008 (earlier it
> > was 0006).
> >
>
> The code changes look fine but it is not clear what was the exact
> issue.  Can you explain?

Basically, in case of an empty subtransaction, we were reading the
subxacts info but when we could not find the subxid in the subxacts
info we were not releasing the memory.  So on next subxact_info_read
it will expect that subxacts should be freed but we did not free it in
that !found case.

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