Re: Issues with ON CONFLICT UPDATE and REINDEX CONCURRENTLY

On Mon, Nov 24, 2025 at 06:49:47PM +0100, Alvaro Herrera wrote:
> This patch would bring the committed test file up to date with what you
> last submitted. However, I didn't understand what is the problem with
> the original formulation, and I haven't seen the test fail ... can you
> explain?

Reading through bc32a12e0db2, I am puzzled by the committed result
here:
+#ifdef USE_INJECTION_POINTS
+ if (conflict)
+ INJECTION_POINT("check-exclusion-or-unique-constraint-conflict", NULL);
+ else
+ INJECTION_POINT("check-exclusion-or-unique-constraint-no-conflict", NULL);
+#endif

The "no-conflict" point is used in the isolation test, but not the
other in the "conflict == true" path:
$ git grep check-exclusion-or-unique-constraint-conflict
src/backend/executor/execIndexing.c:
INJECTION_POINT("check-exclusion-or-unique-constraint-conflict", NULL);

If you have no plans for it in the long-term, I'd rather remove it
from the tree, rather than keep it. Of course, I would keep the
USE_INJECTION_POINTS block to avoid the extra boolean check in
non-USE_INJECTION_POINTS builds.
--
Michael