Re: Add an option to skip loading missing publication to avoid logical replication failure

On Fri, 14 Feb 2025 at 15:36, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> Did you try to measure the performance impact of this change? We can
> try a few cases where DDL and DMLs are involved, missing publication
> (drop publication and recreate after a varying number of records to
> check the impact).

Since we don't have an exact scenario to compare with the patch
(because, in the current HEAD, when the publication is missing, an
error is thrown and the walsender/worker restarts), I compared the
positive case, where records are successfully replicated to the
subscriber, as shown below. For the scenario with the patch, I ran the
same test, where the publication is dropped before the insert,
allowing the walsender to check whether the publication is present.
The test results, which represent the median of 7 runs and the
execution run is in milliseconds, are provided below:

Brach/records | 100 | 1000 | 10000 | 100000 | 1000000
Head | 1.214 | 2.548 | 10.823 | 90.3 | 951.833
Patch | 1.215 | 2.5485 | 10.8545 | 90.94 | 955.134
% diff | 0.082 | 0.020 | 0.291 | 0.704 | 0.347

I noticed that the test run with patches is very negligible. The
scripts used for execution are attached.

> The other names for the option could be:
> skip_notexistant_publications, or ignore_nonexistant_publications. Can
> we think of any others?

How about using ignore_missing_publications or skip_missing_publications?

Regards,
Vignesh