Introduction to Enterprise Access
The Enterprise Access products, also referred to as gateways, are designed to provide access to popular database systems on Windows and UNIX. The Enterprise Access server implements an interface similar in appearance and behavior to each of the supported DBMS systems. This allows a single Enterprise Access client application to be used to access all of these data sources. The application does not know about the characteristics of the database system that it is accessing.
This approach allows the developer to build portable applications that can be used to access any supported database at run time. Thus, a single application can support access to Ingres, Microsoft SQL Server, Oracle, and DB2 UDB.
The following components are required for this approach:
• OpenSQL is a common dialect of SQL that is implemented by the Enterprise Access servers and is used by the client to access data in the supported DBMS systems
• The Standard Catalog Interface is used to provide a common meta data interface to the native DBMS catalogs
• A common messaging protocol, GCF (Generalized Communication Facility), is used to provide a common platform and location independent interface to the Enterprise Access servers
These items allow the creation of an application that can be written once and deployed against any supported database on any supported platform.
For restrictions that apply to a particular host DBMS, see Developing Portable Applications.