| From: | Michail Nikolaev <michail(dot)nikolaev(at)gmail(dot)com> |
|---|---|
| To: | "Zhijie Hou (Fujitsu)" <houzj(dot)fnst(at)fujitsu(dot)com> |
| Cc: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>, "Hayato Kuroda (Fujitsu)" <kuroda(dot)hayato(at)fujitsu(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>, Andres Freund <andres(at)anarazel(dot)de> |
| Subject: | Re: [BUG?] check_exclusion_or_unique_constraint false negative |
| Date: | 2024-08-12 11:11:26 |
| Message-ID: | CANtu0oiziTBM8+WDtkktMZv0rhGBroYGWwqSQW+MzOWpmk-XEw@mail.gmail.com |
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| Lists: | pgsql-hackers |
Hello, Hou zj!
> In my test, if the tuple is updated and new tuple is in the same page,
> heapam_index_fetch_tuple should find the new tuple using HOT chain. So,
it's a
> bit unclear to me how the updated tuple is missing. Maybe I missed some
other
> conditions for this issue.
Yeah, I think the pgbench-based reproducer may also cause page splits in
btree.
But we may add an index to the table to disable HOT.
I have attached a reproducer for this case using a spec and injection
points.
I hope it helps, check the attached files.
Best regards,
Mikhail.
| Attachment | Content-Type | Size |
|---|---|---|
| v2-0002-additional-test-spec-to-reproduce-dirty-snapshot-.patch | text/x-patch | 5.8 KB |
| v2-0001-fix-for-lost-record-in-case-of-DirtySnapshot-inde.patch | text/x-patch | 16.6 KB |
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