Re: Fix REPACK with WITHOUT OVERLAPS replica identity indexes

On Fri, 8 May 2026 at 09:22, Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> wrote:
>
> Hi,
>
> While testing UPDATE FOR PORTION OF, I started wondering whether REPACK supports temporal tables. In theory, it should, because temporal WITHOUT OVERLAPS indexes can be used as replica identity indexes. So I created a test script, repack_temporal.spec, which is included in the attached patch, and it failed.
>
> I found that REPACK hard-codes BTEqualStrategyNumber when calling get_opfamily_member(). That seems wrong, because build_replindex_scan_key() uses IndexAmTranslateCompareType() to get the equality strategy for COMPARE_EQ.
>
> After fixing the hard-coded BTEqualStrategyNumber, the temporal test passed. Then I added another test for multirange, repack_temporal_multirange.spec, which also failed. The reason is that find_target_tuple() uses the identity index to find the first tuple and returns it directly, but a lossy index scan may return false positives and require recheck.
>
> Please see the attached patch for the fix details and test scripts.
>
> Best regards,
> --
> Chao Li (Evan)
> HighGo Software Co., Ltd.
> https://www.highgo.com/
>

your analysis appears correct to me

> + while (index_getnext_slot(scan, ForwardScanDirection, retrieved))
> + {
> + if (scan->xs_recheck && !identity_key_equal(chgcxt, locator, retrieved))
> + continue;
> +
> + retval = true;
> + break;
> + }

Should we add CFI() ?

Also, do we really need isolation tests and inj points here? Doesn't a
simple regression test for REPACK execute the same code?

--
Best regards,
Kirill Reshke