• If the database resides on a Btrfs file system, you should consider disabling Copy-on-Write for the directory before creating any database.
• If the database resides on a ZFS file system, you should consult ZFS hints for databases before creating any database.

SHOW max_parallel_workers_per_gather;
SHOW max_parallel_workers;
SET max_parallel_workers_per_gather = 0;
SET max_parallel_workers = 0;