8.1.2.First Generation Virtual Database Products
Although the strict VDB definition may be new, there are a number of products that have been around for a while that attempt to address VDB issues. The list of such products includes The Microsoft JET Engine, Borland Database Engine (BDE), and IBM DataJoiner.
Microsoft JET
The Microsoft JET Engine lies at the heart of Microsoft Access, it is the piece of technology that allows you to link external and typically remote database tables into your local Access space via ODBC Data Sources. Once this link process has been completed, Access allows you to build Queries, Reports, Forms etc. using these external database tables as though they were Local Access tables. JET can also link to external tables hosted within desktop database engines via native interfaces.
The Microsoft JET Engine services are exposed via Microsoft provided data access interfaces such as: DAO, ADO, and OLE-DB. These interfaces are integral parts of most Microsoft applications, thereby exposing the benefits of the JET VDB transparently.
Borland Database Engine
The Borland Database Engine (BDE) from Inprise like the Microsoft JET Engine also facilitates external table linkage via ODBC Data Sources. The BDE also lets you link to external database tables via native database interfaces and there is no restriction to desktop database engines when you adopt this approach.
Although the BDE has a published set of APIs, it is predominantly used by Inprise applications in very much the same way JET is used by Microsoft applications.
IBM DataJoiner
DataJoiner from IBM provides the ability access heterogeneous data sources via IBM DB/2 Client Application Enablers. It does support ODBC and JDBC as client interfaces and makes use of Native or ODBC based data access for external Data I/O.