The Open interface of BI Server gives the possibilities to made a client connection throught ODBC and JDBC.
Clients of the Oracle BI Server see a logical schema view independent of the source physical database schemas. Oracle BI Server clients submit simplified logical SQL, which ultimately gets translated by the server to some combination of physical SQL sent to the back-end databases, in addition to intermediate processing within the Oracle BI Server Execution Engine.
By default, OBIEE provides several ODBC clients:
which permit you to made ODBC calls via the Analytics ODBC driver such as an odbc function.
Any Jdbc client can easily made a JDBC connection with the BI Jdbc driver.