Horton

Re: Why is subscription/t/031_column_list.pl failing so much?

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alexander Lakhin <exclusion@gmail.com>, Noah Misch <noah@leadboat.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-02-07T09:51:18Z
Lists: pgsql-hackers 
On Tue, Feb 6, 2024 at 8:21 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Amit Kapila <amit.kapila16@gmail.com> writes:
> > Yeah, I was worried about that. The other idea I have previously
> > thought was to change Alter Subscription to Drop+Create Subscription.
> > That should also help in bringing stability without losing any
> > functionality.
>
> Hm, why would that fix it?
>

Because for new subscriptions, we will start reading WAL from the
latest WAL insert pointer on the publisher which will be after the
point where publication is created.

> More to the point, aren't these proposals just band-aids that
> would stabilize the test without fixing the actual problem?

Yes, but OTOH, this behavior has been since the beginning of logical
replication. This particular test has just exposed it, so keeping BF
failing for this particular test doesn't sound like the best way to
remember it.

-- 
With Regards,
Amit Kapila.

Commits

  1. Back-patch test modifications that were done as part of b6df0798a5.

  2. Fix the intermittent buildfarm failures in 031_column_list.

  3. Fix test race between primary XLOG_RUNNING_XACTS and standby logical slot.

  4. Bound waits in 035_standby_logical_decoding.pl.