> On May 9, 2026, at 01:47, Kirill Reshke <[email protected]> wrote: > > On Fri, 8 May 2026 at 09:22, Chao Li <[email protected]> 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
Hi Kirill, thanks for your review.
>
>> + 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() ?
>
Oh, I didn’t consider that at all, because I thought there should not be a lot
of candidate rows needing recheck. I am okay to add that.
>
> Also, do we really need isolation tests and inj points here?
I think so. Without the injection point, the first phase of copying a new heap
would be very fast, it would be hard to run an update in the second session. I
think that’s way the repack code intentionally added an injection point before
the first round of replay:
```
/*
* During testing, wait for another backend to perform concurrent data
* changes which we will process below.
*/
INJECTION_POINT("repack-concurrently-before-lock", NULL);
```
> Doesn't a
> simple regression test for REPACK execute the same code?
>
It seems we intentionally avoid to run repack test in the regress test, see [1]
and [2].
PFA v2: added the CFI as Kirill suggested.
[1] https://postgr.es/m/[email protected]
[2]
https://git.postgresql.org/cgit/postgresql.git/commit/?id=2fd787d0aac1cb00a42ebce92ebb1d7534035ee3
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
v2-0001-Fix-REPACK-with-WITHOUT-OVERLAPS-replica-identity.patch
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