Please note that delete query in place of Truncate is working fine but there is a performance issue because the delete query like below is not having where clause so trying to acquire lock on whole table and deleting one row at a time there by causing performance issue at PEGA level and deadlock issue at DB level.
Truncate commands do not write to the redo logs so they need to be in a separate transaction. You should create a stored procedure which does the commit followed by the truncate and then call the stored procedure from your RDB
I don't see anything obviously wrong with the syntax you have. I would try it without the "" around the schema and table name. Also make sure that you have changed the default delimiter in whatever tool you are using to be any special character other than semicolon.