If you write a script that modifies the structure of any tables involved in your query and then try to add or update rows in the query's result table, the results are unpredictable.

The default transaction action for IBM database managers is a commit when you close a database or database manager. The default transaction action for non-IBM database managers is a commit for each execute, unless a begin, commit, or rollback was done.

Any time you change table definitions, you should start your database manager again to ensure that the new definitions are used.