User report: after upgrade from 11.4.5 to 11.4.6 some tables were not working

Extracted from MDEV-36765. raulk89 wrote:

After the upgrade, one database had 3 table's, which were totally broken (some sort of corruption). I wasn't able to query not a single row from those tables, all querys were hanged, and they were not possible to kill as well. All sessionas had "Killed" as status. Database restart was not possible, I had to kill mariadb process to get database restarted each time.
So there was some corruption happening on these 3 tables. I was not able to dump even the database data using mariadb-dump, the dump command also hanged, when it tried to dump those 3 tables.
Finally, after the numerous db restarts , I was able to save one table, by randomly dropping 2 constraints on that table. Also, the table must not have had any querys running, because each new select, will take lock on table, and then no DDL statement (alter..) were working. So the applicaton had to have been stopped the entire time. Then this table was accessible and I also was able to recreate those constraints.

For the other 2 tables, I had no other option, I had to drop those and recreate from scratch. I had 1:00 AM backup and used this to restore those. So the database was all fine on 1:00 AM, because db dump then was executed successfully !

The database upgrade happened 3:00 AM
And after that everything was broken.

Also mariadbd process was 100+% all the time after the upgrade, which was strange. I tried also to create new database for the affected one and use 1:00 AM backup for this, to get it working, but when I started the import, then this process run very slowly and produced locks for all other databases as well. I let it run like 5 minutes, and it was only on second or third table. Entire dump was around ~400MB. So by then I understood, that this is not going to work, and I cancelled the import immediately.

When I managed to fix all those 3 table corruptions, then mariadbd process utilization reduced drastically. it seemed like all was working then. But I still reverted to 11.4.5 to be safe. I just did not want entire thing happening again today.