Important Database Engines

At the lowest level are the database engines. These are sometimes called “back ends,” but that’s a bit sloppy since the term “back end” really refers to a specific physical architecture. These are the gadgets that will handle the physical manipulation of data—storing it to disk and feeding it back on demand. We’ll be looking at two: the Jet database engine and SQL Server.

You may be surprised not to see Microsoft Access here. Access uses the Jet database engine to manipulate data stored in .mdb files and can link to and manipulate data stored in any ODBC data source, including SQL Server. Access has always used the Jet database engine, although Microsoft didn’t expose the engine as a separate entity until the release of Microsoft Visual Basic 3. With the introduction of support for ODBCDirect in Access 97 and support for SQL Server in Access 2000, Microsoft has begun to uncouple the Access front-end tools from the Jet database engine, and I expect this trend to continue in future releases. (But don’t quote me.)

The Jet database engine and SQL Server, although very different, are both wonderful tools for storing and manipulating data. The difference between them lies in their architectures and the problems they are intended to address. Microsoft Jet is a “desktop” database engine, intended for small-sized to medium-sized systems. SQL Server, on the other hand, uses a client/server architecture and is intended for medium-sized to huge systems, scalable to potentially thousands of users running mission-critical applications. (Note please that this does not imply that the Jet database engine is appropriate only for trivial systems.)