Oracle Database Gateways provide the ability to transparently access data residing in a non-Oracle system from an Oracle environment. These sections briefly cover Heterogeneous Services, the technology on which the Oracle Database Gateway for SQL Server is based.

To get a good understanding of generic gateway technology, Heterogeneous Services, and how Oracle Database Gateways fit in the picture, reading Oracle Database Heterogeneous Connectivity User's Guide first is highly recommended.

• Overview of Oracle Database Gateways
  Oracle Database Gateways provide the ability to transparently access data residing in a non-Oracle system from an Oracle environment.
• About Heterogeneous Services Technology
  Heterogeneous Services provides the generic technology for connecting to non-Oracle systems.
• About Oracle Database Gateway for SQL Server
  The capabilities, SQL mappings, data type conversions, and interface to the remote non-Oracle system are contained in the gateway.