Re: HOT chain validation in verify_heapam()

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>

To: pgsql-hackers@lists.postgresql.org, Peter Geoghegan <pg@bowt.ie>

Cc: Himanshu Upadhyaya <upadhyaya.himanshu@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Aleksander Alekseev <aleksander@timescale.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>

Date: 2022-11-10T02:10:49Z

Lists: pgsql-hackers

Hi,

And thinking about it, it'd be quite bad if the horizon worked that way. You can easily construct a workload where every single xid would "skewer" some chain, never allowing the horizon to be raised.

Andres
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Commits

amcheck: Generalize one of the recently-added update chain checks.
- c87aff065c33 16.0 landed
amcheck: Tighten up validation of redirect line pointers.
- 80d5e3a61551 16.0 landed
amcheck: Fix verify_heapam for tuples where xmin or xmax is 0.
- 8fd5aa76c367 14.8 landed
- 701ec5557968 15.3 landed
- e88754a1965c 16.0 landed
amcheck: Fix a few bugs in new update chain validation.
- 949e2e7c4f68 16.0 landed
Fix new test case to work on (some?) big-endian architectures.
- c75a623304bc 16.0 landed
Don't test HEAP_XMAX_INVALID when freezing xmax.
- 02d647bbf057 16.0 landed