@psbkb, usually it's because another

osqueryd

is running, if you can:

$ sudo osqueryi
osquery> select * from process_open_files where path like '%osquery.db/LOCK';
+-------+----+------------------------------+
| pid   | fd | path                         |
+-------+----+------------------------------+
| 16960 | 4  | /var/osquery/osquery.db/LOCK |
+-------+----+------------------------------+