Customer reported:

We have 2UM, 2PM system and one of the DDL statements appeared to have an issue during a truncate. The table stays locked by DDL and cannot be cleared. The Truncate looks like it worked, however, as there is no error in the logs and the table is empty.

[root@usfit-scdb1 bin]# ./viewtablelock
There is 1 table lock

Table LockID Process PID Session Txn CreationTime State DBRoots
dairy.dairy_collection_relationship 103583 DDLProc 43080 151725 1270108 Wed Jun 19 14:32:01 2019 LOADING 1,2
[root@usfit-scdb1 bin]# ./cleartablelock 103583
Rolling back and clearing table lock for table dairy.dairy_collection_relationship; table lock 103583

Rollback error: Unable to grab lock; Lock not found or still in use.
Table lock 103583 for table dairy.dairy_collection_relationship is not cleared.

1. they did a restart of DMLProc and it didnt clear
2. they then did a restartsystem and it had this effect

A restart of the system left the table locked, but changed the LockID to 1. We were able to clear the lock at that point.

It is still curious how this 'hanging' lock came into play, as it appears the statements that it failed on did indeed truncate the table.

I got a support report for the issue and there was no errors logged at the time they believe the lock took place.