Description:
When defining a concept with a multiple String property in TIBCO BusinessEvents (BE), and setting the property with a '' value, this value will be stored in the Oracle backing store. Oracle automatically converts all ''(empty strings) to null. After restarting of BE, BE does  not return any of the null value properties from the backing store.

Symptoms:
When defining a concept with a multiple String property, and setting the property with a '' value, the value will be stored in the Oracle backing store and Oracle automatically converts all ''(empty strings) to null. After restarting be-engine, be-engine does not return any of the null value properties from the backing store.
Cause:
Identified as a product defect. ( BE-17544 and BE-18377) .HF available (see the resolution notes below).

TIBCO BusinessEvents cannot return Property Arrays with empty values from backing store after restarting.

1). The fix is available in BE 5.1.1 HF2 and upgrading to BE 5.2.0 and onward.
2). If upgrading to 5.x is not an option, the workaround for the issue is to replace null strings ("") with some specific constant, such as $NULL.