Horton

Re: Sync scan & regression tests

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, David Rowley <dgrowleyml@gmail.com>, Melanie Plageman <melanieplageman@gmail.com>, Konstantin Knizhnik <knizhnik@garret.ru>, pgsql-hackers@lists.postgresql.org, Thomas Munro <thomas.munro@gmail.com>
Date: 2023-09-05T03:16:48Z
Lists: pgsql-hackers 
Heikki Linnakangas <hlinnaka@iki.fi> writes:
> With shared_buffers='20MB', the tests passed. I'm going to change it 
> back to 10MB now, so that we continue to cover that case.

So chipmunk is getting through the core tests now, but instead it
is failing in contrib/pg_visibility [1]:

diff -U3 /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/expected/pg_visibility.out /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/results/pg_visibility.out
--- /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/expected/pg_visibility.out	2022-10-08 19:00:15.905074105 +0300
+++ /home/pgbfarm/buildroot/HEAD/pgsql.build/contrib/pg_visibility/results/pg_visibility.out	2023-09-02 00:25:51.814148116 +0300
@@ -218,7 +218,8 @@
      0 | t           | t
      1 | t           | t
      2 | t           | t
-(3 rows)
+     3 | f           | f
+(4 rows)
 
 select * from pg_check_frozen('copyfreeze');
  t_ctid 

I find this easily reproducible by setting shared_buffers=10MB.
But I'm confused about why, because the affected test case
dates to Tomas' commit 7db0cd214 of 2021-01-17, and chipmunk
passed many times after that.  Might be worth bisecting in
the interval where chipmunk wasn't reporting?

			regards, tom lane

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=chipmunk&dt=2023-09-01%2015%3A15%3A56

Commits

  1. Avoid edge case in pg_visibility test with small shared_buffers

  2. Report syncscan position at end of scan.

  3. hio: Take number of prior relation extensions into account

  4. Reduce code duplication between heapgettup and heapgettup_pagemode

  5. Fix CLUSTER tuplesorts on abbreviated expressions.

  6. Set PD_ALL_VISIBLE and visibility map bits in COPY FREEZE