PropertyHandle :: IsExtent - Does property handle refer to an extent?
The function returns true (YES), when the property handle refers to a database or temporary extent. The function returns false (NO), when the property handle is not valid, when the property handle is a handle for a sub-property or when the property handle refers to a transient extent (collection) or to an access path or expression (query).
Return value: Return value ( logical )
The function returns YES when the question was answered positively. Otherwise it returns NO.