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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: Rahila Syed <rahilasyed90@gmail.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, Peter Smith <smithpb2250@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2021-07-22T18:48:32Z
Lists: pgsql-hackers 
One thing I just happened to notice is this part of your commit message

: REPLICA IDENTITY columns are always replicated
: irrespective of column names specification.

... for which you don't have any tests -- I mean, create a table with a
certain REPLICA IDENTITY and later try to publish a set of columns that
doesn't include all the columns in the replica identity, then verify
that those columns are indeed published.

Having said that, I'm not sure I agree with this design decision; what I
think this is doing is hiding from the user the fact that they are
publishing columns that they don't want to publish.  I think as a user I
would rather get an error in that case:

  ERROR:  invalid column list in published set
  DETAIL:  The set of published commands does not include all the replica identity columns.

or something like that.  Avoid possible nasty surprises of security-
leaking nature.

-- 
Álvaro Herrera           39°49'30"S 73°17'W  —  https://www.EnterpriseDB.com/
"On the other flipper, one wrong move and we're Fatal Exceptions"
(T.U.X.: Term Unit X  - http://www.thelinuxreview.com/TUX/)

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