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Re: Column Filtering in Logical Replication

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: vignesh C <vignesh21@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Rahila Syed <rahilasyed90@gmail.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Peter Smith <smithpb2250@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2021-09-16T13:50:25Z
Lists: pgsql-hackers 
On 2021-Sep-16, vignesh C wrote:

> diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
> index e3068a374e..c50bb570ea 100644
> --- a/src/backend/parser/gram.y
> +++ b/src/backend/parser/gram.y

Yeah, on a quick glance this looks all wrong.  Your PublicationObjSpec
production should return a node with tag PublicationObjSpec, and
pubobj_expr should not exist at all -- that stuff is just making it all
more confusing.

I think it'd be something like this:

PublicationObjSpec:	
			ALL TABLES
					{
						$$ = makeNode(PublicationObjSpec);
						$$->pubobjtype = PUBLICATIONOBJ_ALL_TABLES;
						$$->location = @1;
					}
			| TABLE qualified_name
					{
						$$ = makeNode(PublicationObjSpec);
						$$->pubobjtype = PUBLICATIONOBJ_TABLE;
						$$->pubobj = $2;
						$$->location = @1;
					}
			| ALL TABLES IN_P SCHEMA name
					{
						$$ = makeNode(PublicationObjSpec);
						$$->pubobjtype = PUBLICATIONOBJ_ALL_TABLES_IN_SCHEMA;
						$$->pubobj = makeRangeVar( ... $5 ... );
						$$->location = @1;
					}
			| qualified_name
					{
						$$ = makeNode(PublicationObjSpec);
						$$->pubobjtype = PUBLICATIONOBJ_CONTINUATION;
						$$->pubobj = $1;
						$$->location = @1;
					};

You need a single object name under TABLE, not a list -- this was Tom's
point about needing post-processing to determine how to assign a type to
a object that's what I named PUBLICATIONOBJ_CONTINUATION here.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"Puedes vivir sólo una vez, pero si lo haces bien, una vez es suficiente"

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Doc: Explain about Column List feature.

  2. Doc: fix column list vs. replica identity rules.

  3. Prohibit combining publications with different column lists.

  4. Fix the check to limit sync workers.

  5. Wait for subscription to sync in t/031_column_list.sql

  6. Move prattrs to the pg_publication_rel section in docs

  7. Allow specifying column lists for logical replication

  8. Fix row filters with multiple publications

  9. Fix publish_as_relid with multiple publications

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

  11. Add index on pg_publication_rel.prpubid

  12. Avoid using DefElemAction in AlterPublicationStmt

  13. Small cleanups related to PUBLICATION framework code

  14. Add PublicationTable and PublicationRelInfo structs

  15. Fix various concurrency issues in logical replication worker launching