RE: row filtering for logical replication

Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>

From: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>, Amit Kapila <amit.kapila16@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, Euler Taveira <euler@eulerto.com>, Greg Nancarrow <gregn4422@gmail.com>, vignesh C <vignesh21@gmail.com>, Ajin Cherian <itsajin@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Önder Kalacı <onderkalaci@gmail.com>, japin <japinli@hotmail.com>, Michael Paquier <michael@paquier.xyz>, David Steele <david@pgmasters.net>, Craig Ringer <craig@2ndquadrant.com>, Amit Langote <amitlangote09@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-01-21T05:21:58Z
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. Release cache tuple when no longer needed

  2. Add some additional tests for row filters in logical replication.

  3. Fix one of the tests introduced in commit 52e4f0cd47.

  4. Allow specifying row filters for logical replication of tables.

  5. Move scanint8() to numutils.c

  6. Replace Test::More plans with done_testing

  7. Reduce relcache access in WAL sender streaming logical changes

  8. Small cleanups related to PUBLICATION framework code

  9. Add a view to show the stats of subscription workers.

  10. Allow publishing the tables of schema.

  11. Doc: improve documentation of CREATE/ALTER SUBSCRIPTION.

  12. Add PublicationTable and PublicationRelInfo structs

  13. Remove unused argument "txn" in maybe_send_schema().

  14. Add prepare API support for streaming transactions in logical replication.

  15. Unify PostgresNode's new() and get_new_node() methods

  16. Use l*_node() family of functions where appropriate

  17. Add support for prepared transactions to built-in logical replication.

  18. Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.

  19. Rename a parse node to be more general

  20. Remove unused column atttypmod from initial tablesync query

  21. SEARCH and CYCLE clauses

On Thur, Jan 20, 2022 10:26 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> 
> On 2022-Jan-20, Amit Kapila wrote:
> 
> > It returns an invalid column referenced in an RF if any but if not
> > then it helps to form pubactions which is anyway required at a later
> > point in the caller. The idea is that when we are already traversing
> > publications we should store/gather as much info as possible.
> 
> I think this design isn't quite awesome.
> 
> > I think probably the API name is misleading, maybe we should name it
> > something like ValidateAndFetchPubInfo, ValidateAndRememberPubInfo, or
> > something along these lines?
> 
> Maybe RelationBuildReplicationPublicationDesc or just
> RelationBuildPublicationDesc are good names for a routine that fill in
> the publication aspect of the relcache entry, as a parallel to
> RelationBuildPartitionDesc.
> 
> > >  Maybe this was meant to be "validate RF
> > > expressions" and return, perhaps, a bitmapset of all invalid columns
> > > referenced?
> >
> > Currently, we stop as soon as we find the first invalid column.
> 
> That seems quite strange.  (And above you say "gather as much info as
> possible", so why stop at the first one?)
> 
> > >  (What is an invalid column in the first place?)
> >
> > A column that is referenced in the row filter but is not part of
> > Replica Identity.
> 
> I do wonder how do these invalid columns reach the table definition in
> the first place.  Shouldn't these be detected at DDL time and prohibited
> from getting into the definition?

Personally, I'm a little hesitant to put the check at DDL level, because
adding check at DDLs like ATTACH PARTITION/CREATE PARTITION OF ( [1]
explained why we need to check these DDLs) looks a bit restrictive and
user might also complain about that. Put the check in
CheckCmdReplicaIdentity seems more acceptable because it is consistent
with the existing behavior which has few complaints from users AFAIK.

[1] https://www.postgresql.org/message-id/CAA4eK1%2Bm45Xyzx7AUY9TyFnB6CZ7_%2B_uooPb7WHSpp7UE%3DYmKg%40mail.gmail.com

Best regards,
Hou zj