Re: row filtering for logical replication

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>
Cc: Peter Smith <smithpb2250@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: 2022-02-02T07:07:25Z
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 Tue, Feb 1, 2022 at 4:51 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> Review Comments:
> ===============
> 1.
> + else if (IsA(node, OpExpr))
> + {
> + /* OK, except user-defined operators are not allowed. */
> + if (((OpExpr *) node)->opno >= FirstNormalObjectId)
> + errdetail_msg = _("User-defined operators are not allowed.");
> + }
>
> Is it sufficient to check only the allowed operators for OpExpr? Don't
> we need to check opfuncid to ensure that the corresponding function is
> immutable? Also, what about opresulttype, opcollid, and inputcollid? I
> think we don't want to allow user-defined types or collations but as
> we are restricting the opexp to use a built-in operator, those should
> not be present in such an expression. If that is the case, then I
> think we can add a comment for the same.
>

Today, I was looking at a few other nodes supported by the patch and I
have similar questions for those as well. As an example, the patch
allows T_ScalarArrayOpExpr and the node is as follows:

typedef struct ScalarArrayOpExpr
{
Expr xpr;
Oid opno; /* PG_OPERATOR OID of the operator */
Oid opfuncid; /* PG_PROC OID of comparison function */
Oid hashfuncid; /* PG_PROC OID of hash func or InvalidOid */
Oid negfuncid; /* PG_PROC OID of negator of opfuncid function
* or InvalidOid.  See above */
bool useOr; /* true for ANY, false for ALL */
Oid inputcollid; /* OID of collation that operator should use */
List    *args; /* the scalar and array operands */
int location; /* token location, or -1 if unknown */
} ScalarArrayOpExpr;

Don't we need to check pg_proc OIDs like hashfuncid to ensure that it
is immutable like the patch is doing for FuncExpr? Similarly for
ArrayExpr node, don't we need to check the array_collid to see if it
contains user-defined collation? I think some of these might be okay
to permit but then it is better to have some comments to explain.

--
With Regards,
Amit Kapila.