Re: collect_corrupt_items_vacuum.patch

Hi Alexander,

06.11.2023 12:30, Alexander Korotkov wrote:
> Surely these would significantly sacrifice accuracy. But we have to do
> so in order to avoid reporting false errors.
>

I've reduced the dirty reproducer Daniel Shelepanov posted initially
to the following:
numdbs=10
for ((d=1;d<=$numdbs;d++)); do
  createdb db$d
  psql db$d -c "create extension pg_visibility"
done

for ((i=1;i<=300;i++)); do
echo "iteration $i"
for ((d=1;d<=$numdbs;d++)); do
(
echo "
create table vacuum_test as select 42 i;
vacuum (disable_page_skipping) vacuum_test;
select * from pg_check_visible('vacuum_test');
" | psql db$d -a -q >psql-$d.log 2>&1
) &
done
wait

res=0
for ((d=1;d<=$numdbs;d++)); do
grep -q '0 rows' psql-$d.log || { echo "Error condition in psql-$d.log:"; cat psql-$d.log; res=1; break; }
psql db$d -q -c "drop table vacuum_test"
done
[ $res == 0 ] || break;
done

It looks like the v2 patch doesn't fix the original issue. Maybe I miss
something, but with the patch applied, I see the failure immediately,
though without the patch several iterations are needed to get it.

Best regards,
Alexander