Horton

RE: row filtering for logical replication

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

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From: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>
To: Peter Smith <smithpb2250@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Euler Taveira <euler@eulerto.com>, Greg Nancarrow <gregn4422@gmail.com>, vignesh C <vignesh21@gmail.com>, Ajin Cherian <itsajin@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.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: 2022-01-26T03:07:18Z
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 Monday, January 24, 2022 4:38 PM Peter Smith <smithpb2250@gmail.com> wrote:
> 
> Thanks for all the patches!
> 
> Here are my review comments for v69-0001
> 
> ~~~
> 
> 1. src/backend/executor/execReplication.c  CheckCmdReplicaIdentity call to
> RelationBuildPublicationDesc
> 
> + /*
> + * It is only safe to execute UPDATE/DELETE when all columns,
> + referenced in
> + * the row filters from publications which the relation is in, are
> + valid -
> + * i.e. when all referenced columns are part of REPLICA IDENTITY or the
> + * table does not publish UPDATES or DELETES.
> + */
> + pubdesc = RelationBuildPublicationDesc(rel);
> 
> This code is leaky because never frees the palloc-ed memory for the pubdesc.
> 
> IMO change the RelationBuildPublicationDesc to pass in the
> PublicationDesc* from the call stack then can eliminate the palloc and risk of
> leaks.
> 
> ~~~
> 
> 2. src/include/utils/relcache.h - RelationBuildPublicationDesc
> 
> +struct PublicationDesc;
> +extern struct PublicationDesc *RelationBuildPublicationDesc(Relation
> +relation);
> 
> (Same as the previous comment #1). Suggest to change the function signature
> to be void and pass the PublicationDesc* from stack instead of palloc-ing it
> within the function

Changed in V71.

> 
> 3. src/backend/utils/cache/relcache.c - RelationBuildPublicationDesc
> 
> +RelationBuildPublicationDesc(Relation relation)
>  {
>   List    *puboids;
>   ListCell   *lc;
>   MemoryContext oldcxt;
>   Oid schemaid;
> - PublicationActions *pubactions = palloc0(sizeof(PublicationActions));
> + List    *ancestors = NIL;
> + Oid relid = RelationGetRelid(relation); AttrNumber invalid_rfcolnum =
> + InvalidAttrNumber; PublicationDesc *pubdesc =
> + palloc0(sizeof(PublicationDesc)); PublicationActions *pubactions =
> + &pubdesc->pubactions;
> +
> + pubdesc->rf_valid_for_update = true;
> + pubdesc->rf_valid_for_delete = true;
> 
> IMO it wold be better to change the "sense" of those variables.
> e.g.
> 
> "rf_valid_for_update" --> "rf_invalid_for_update"
> "rf_valid_for_delete" --> "rf_invalid_for_delete"
> 
> That way they have the same 'sense' as the AttrNumbers so it all reads better to
> me.
> 
> Also, it means no special assignment is needed because the palloc0 will set
> them correctly

Think again, I am not sure it's better to have an invalid_... flag.
It seems more natural to have a valid_... flag.

Best regards,
Hou zj