Re: BitmapHeapScan streaming read user and prelim refactoring - Mailing list pgsql-hackers

On Thu, Mar 13, 2025 at 5:41 PM Melanie Plageman
<melanieplageman@gmail.com> wrote:

Overall, I feel pretty good about merging this once Thomas merges the
read stream patches.

This was committed in 944e81bf99db2b5b70b, 2b73a8cd33b745c, and
c3953226a07527a1e2.
I've marked it as committed in the CF app.

It looks like that change made the bitmapops test unstable (on slow animals?): [1], [2], [3].
I've reproduced such test failures when running
TESTS=$(printf 'bitmapops %.0s' `seq 50`) make -s check-tests
under Valgrind:
...
ok 17        - bitmapops                               52719 ms
not ok 18    - bitmapops                               57566 ms
ok 19        - bitmapops                               60179 ms
ok 20        - bitmapops                               32927 ms
ok 21        - bitmapops                               45127 ms
ok 22        - bitmapops                               42924 ms
ok 23        - bitmapops                               61035 ms
ok 24        - bitmapops                               56316 ms
ok 25        - bitmapops                               52874 ms
not ok 26    - bitmapops                               67468 ms
ok 27        - bitmapops                               55605 ms
ok 28        - bitmapops                               24021 ms
...

diff -U3 /home/vagrant/postgresql/src/test/regress/expected/bitmapops.out /home/vagrant/postgresql/src/test/regress/results/bitmapops.out
--- /home/vagrant/postgresql/src/test/regress/expected/bitmapops.out    2025-03-16 01:37:52.716885600 -0700
+++ /home/vagrant/postgresql/src/test/regress/results/bitmapops.out     2025-03-22 03:47:54.014702406 -0700
@@ -24,14 +24,14 @@
 SELECT count(*) FROM bmscantest WHERE a = 1 AND b = 1;
  count
 -------
-    23
+    18
 (1 row)

 -- Test bitmap-or.
 SELECT count(*) FROM bmscantest WHERE a = 1 OR b = 1;
  count
 -------
-  2485
+  1044
 (1 row)

 -- clean up
diff -U3 /home/vagrant/postgresql/src/test/regress/expected/bitmapops.out /home/vagrant/postgresql/src/test/regress/results/bitmapops.out
--- /home/vagrant/postgresql/src/test/regress/expected/bitmapops.out    2025-03-16 01:37:52.716885600 -0700
+++ /home/vagrant/postgresql/src/test/regress/results/bitmapops.out     2025-03-22 03:54:53.129549597 -0700
@@ -31,7 +31,7 @@
 SELECT count(*) FROM bmscantest WHERE a = 1 OR b = 1;
  count
 -------
-  2485
+  1044
 (1 row)

git bisect for this deviation has pointed at 2b73a8cd3.

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=skink&dt=2025-03-16%2010%3A34%3A17
[2] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=flaviventris&dt=2025-03-17%2020%3A07%3A43
[3] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=skink&dt=2025-03-17%2001%3A16%3A02

Best regards,
Alexander Lakhin
Neon (https://neon.tech)