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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: Amit Kapila <amit.kapila16@gmail.com>
Cc: vignesh C <vignesh21@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: 2021-09-29T13:19:35Z
Lists: pgsql-hackers 
On 2021-Sep-28, Amit Kapila wrote:

> But it is not allowed to create schema or table with the name
> CURRENT_SCHEMA, so not sure if we need to do anything special for it.

Oh?  You certainly can.

alvherre=# create schema "CURRENT_SCHEMA";
CREATE SCHEMA
alvherre=# \dn
        Listado de esquemas
     Nombre     |       Dueño       
----------------+-------------------
 CURRENT_SCHEMA | alvherre
 public         | pg_database_owner
 temp           | alvherre
(3 filas)

alvherre=# create table "CURRENT_SCHEMA"."CURRENT_SCHEMA" ("bother amit for a while" int);
CREATE TABLE
alvherre=# \d "CURRENT_SCHEMA".*
                  Tabla «CURRENT_SCHEMA.CURRENT_SCHEMA»
         Columna         |  Tipo   | Ordenamiento | Nulable | Por omisión 
-------------------------+---------+--------------+---------+-------------
 bother amit for a while | integer |              |         | 


> Now, during post-processing, the PUBLICATIONOBJ_CONTINUATION will be
> distinguished as CURRENT_SCHEMA because both rangeVar and name will be
> NULL. Do you have other ideas to deal with it?

That sounds plausible.  There's no need for a name-free object of any other
kind AFAICS, so there should be no conflict.  If we ever do find a
conflict, we can add another struct member to disambiguate.

Thanks

-- 
Álvaro Herrera              Valdivia, Chile  —  https://www.EnterpriseDB.com/
"Doing what he did amounts to sticking his fingers under the hood of the
implementation; if he gets his fingers burnt, it's his problem."  (Tom Lane)

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