Why would a customer want to pay for the Oracle Transparent Gateway?

Technically, ODBC is a generic protocol that offers lowest-common-denominator type access. In contrast, the Oracle Transparent Gateways are optimized solutions for specific data sources. Oracle Transparent Gateways use more native connections to the non-Oracle database. As a result, the queries over the database link to the non-Oracle database will be better performing than they would be over ODBC. On a support level, the difference is that with ODBC the customer must obtain and configure the ODBC driver himself. Oracle guarantees support for the ODBC interface, but any problems related to the ODBC driver, e.g. faulty ODBC driver, miss configuration issues, non-availability of ODBC driver for a particular version of the data source, must be addressed by the customer. With the Oracle Transparent Gateways, Oracle offers end-to-end support for accessing a particular data source.  more