Horton

RE: Skipping logical replication transactions on subscriber side

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

View thread View on postgr.es
From: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Greg Nancarrow <gregn4422@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, "osumi.takamichi@fujitsu.com" <osumi.takamichi@fujitsu.com>, Alexey Lesovsky <lesovsky@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Amit Kapila <amit.kapila16@gmail.com>
Date: 2021-09-02T11:37:04Z
Lists: pgsql-hackers

Attachments

From Mon, Aug 30, 2021 3:07 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> I've attached rebased patches. 0004 patch is not the scope of this 
> patch. It's borrowed from another thread[1] to fix the assertion 
> failure for newly added tests. Please review them.

Hi,

I reviewed the 0002 patch and have a suggestion for it.

+				if (IsSet(opts.specified_opts, SUBOPT_SYNCHRONOUS_COMMIT))
+				{
+					values[Anum_pg_subscription_subsynccommit - 1] =
+						CStringGetTextDatum("off");
+					replaces[Anum_pg_subscription_subsynccommit - 1] = true;
+				}

Currently, the patch set the default value out of parse_subscription_options(),
but I think It might be more standard to set the value in
parse_subscription_options(). Like:

			if (!is_reset)
			{
				...
+			}
+			else
+				opts->synchronous_commit = "off";

And then, we can set the value like:

					values[Anum_pg_subscription_subsynccommit - 1] =
						CStringGetTextDatum(opts.synchronous_commit);


Besides, instead of adding a switch case like the following:
+		case ALTER_SUBSCRIPTION_RESET_OPTIONS:
+			{

We can add a bool flag(isReset) in AlterSubscriptionStmt and check the flag
when invoking parse_subscription_options(). In this approach, the code can be
shorter.

Attach a diff file based on the v12-0002 which change the code like the above
suggestion.

Best regards,
Hou zj

Commits

  1. Test ALIGNOF_DOUBLE==4 compatibility under ALIGNOF_DOUBLE==8.

  2. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  3. Add ALTER SUBSCRIPTION ... SKIP.

  4. Optionally disable subscriptions on error.

  5. Update docs of logical replication for commit 8d74fc96db.

  6. Respect permissions within logical replication.

  7. Fix regression test failure caused by commit 8d74fc96db.

  8. Add a view to show the stats of subscription workers.

  9. Add logical change details to logical replication worker errcontext.

  10. Rename LOGICAL_REP_MSG_STREAM_END to LOGICAL_REP_MSG_STREAM_STOP.

  11. Fix typo in protocol.sgml.

  12. Remove unused argument in apply_handle_commit_internal().

  13. Fix replication of in-progress transactions in tablesync worker.

  14. Reorder pg_sequence columns to avoid alignment issue