Re: Allow logical replication to copy tables in binary format - Mailing list pgsql-hackers

From Melih Mutlu
Subject Re: Allow logical replication to copy tables in binary format
Date
Msg-id CAGPVpCSxnLa=uN0nSu+C7_4tJDV6vFNuLLDiXDrviy6uB9Cfpw@mail.gmail.com
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In response to Re: Allow logical replication to copy tables in binary format  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: Allow logical replication to copy tables in binary format  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers


Amit Kapila <amit.kapila16@gmail.com>, 21 Mar 2023 Sal, 09:03 tarihinde şunu yazdı:
On Tue, Mar 21, 2023 at 7:03 AM Peter Smith <smithpb2250@gmail.com> wrote:
>
>
> ======
> src/test/subscription/t/014_binary.pl
>
> 4.
> # -----------------------------------------------------
> # Test mismatched column types with/without binary mode
> # -----------------------------------------------------
>
> # Test syncing tables with mismatching column types
> $node_publisher->safe_psql(
> 'postgres', qq(
>     CREATE TABLE public.test_mismatching_types (
>         a bigint PRIMARY KEY
>     );
>     INSERT INTO public.test_mismatching_types (a)
>         VALUES (1), (2);
>     ));
>
> # Check the subscriber log from now on.
> $offset = -s $node_subscriber->logfile;
>
> # Ensure the subscription is enabled. disable_on_error is still true,
> # so the subscription can be disabled due to missing realtion until
> # the test_mismatching_types table is created.
> $node_subscriber->safe_psql(
> 'postgres', qq(
>     CREATE TABLE public.test_mismatching_types (
>         a int PRIMARY KEY
>     );
> ALTER SUBSCRIPTION tsub ENABLE;
>     ALTER SUBSCRIPTION tsub REFRESH PUBLICATION;
>     ));
>
> ~~
>
> I found the "Ensure the subscription is enabled..." comment and the
> necessity for enabling the subscription to be confusing.
>
> Can't some complications all be eliminated just by creating the table
> on the subscribe side first?
>

Hmm, that would make this test inconsistent with other tests and
probably difficult to understand and extend. I don't like to say this
but I think introducing disable_on_error has introduced more
complexities in the patch due to the requirement of enabling
subscription again and again. I feel it would be better without using
disable_on_error option in these tests.

While this change would make the test inconsistent, I think it also would make more confusing.
Explaining the issue explicitly with a comment seems better to me than the trick of changing order of table creation just for some test cases.
But I'm also ok with removing the use of disable_on_error if that's what you agree on.

Thanks,
--
Melih Mutlu
Microsoft

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