Import Oracle function problem [BOOLEAN not suported?]

Hello,

I have found a problem while importing an Oracle function.

Te Oracle function is like this:

FUNCTION my_oracle_dummie_function (...) RETURN BOOLEAN

While importing in DATASTORES --> Import by name, the problem found was:

Function <MY_ORACLE_DUMMIE_FUNCTION> could not be imported. Possible causes: (1) The return value of the function is not a Data Services supported data type; (2) The function name is not specified or is not a valid database stored procedure or function name; (3) The function is invalid; it has either compilation or authorization errors; (4) It is not supported by the version of the current repository.

How can I import this function? Is it possible import a function returning BOOLEAN?

Thanks in advance.

Enrique Jim Ruiz