increased flakiness in `predicate-rum` test after 1.3.15 release

[thesuhas]

Hi,

After the latest 1.3.15 release, we're seeing increased flakiness in the predicate-rum test. This is not limited to PG18, as we are also seeing failures in PG16 and PG17.

--- /expected/predicate-rum.out	2025-10-23 11:56:59.000000000 +0000
+++ /results/predicate-rum.out	2025-11-07 13:27:13.491494001 +0000
@@ -259,6 +259,7 @@
 step wy2: INSERT INTO rum_tbl(tsv) values('hx');
 step c2: COMMIT;
 step wx1: INSERT INTO rum_tbl(tsv) values('qh');
+ERROR:  could not serialize access due to read/write dependencies among transactions
 step c1: COMMIT;
 
 starting permutation: rxy2 rxy1 wx1 c1 wy2 c2
not ok 1     - predicate-rum                            4384 ms
ok 2         - predicate-rum-2                          5702 ms
1..2
# 1 of 2 tests failed.

[sokolcati]

Hi!
Thanks for the report.

Getting a serialization error on a test with concurrent transactions isn't an index problem. But we should definitely rewrite the test to prevent it from failing in this case.

We'll figure out how to best rework the test.
Thanks.

[thesuhas]

Hi!
Do you have an ETA on a fix/release with a fix?
Thanks