Introduced in April 1994 with Microsoft Access version 2.0, Microsoft Jet version 2.0 offered major enhancements over previous versions. Key areas of improvement included enforced referential integrity and data validation at the engine level, optimized query performance (by using Rushmore technology), increased conformance with ANSI-standard Structured Query Language (SQL) syntax rules, support for UNION, sub-SELECT, and data-definition queries, and a full programming interface to Microsoft Jet by using the DAO version 2.0 object model. Microsoft Jet 2.0 also introduced support for cascading updates and deletions, remote transaction management, SQL pass-through queries, and new MSysConf settings to control how often and how many data fetches are made against ODBC data sources. Additionally, support was added for remote index joins and new initialization file settings for debugging and tuning data operations.
In Microsoft Jet 2.0, the DAO object model was greatly enhanced to provide collections, objects, properties, and methods that gave developers almost complete access to the engine’s underlying services, including support for data definition and manipulation, workspace and transaction management, and programmatic access to security.
Microsoft Jet version 2.5 was introduced in October 1994 in the Microsoft Access 2.0 Service Pack (16-bit) and in the ODBC Desktop Database Drivers Pack version 2.0 (16- and 32-bit). This was the first 32-bit version of the Jet database engine. Many minor features were added to support ODBC desktop database drivers. In addition, the Text and Microsoft Excel data formats were included as true formats rather than formats just for importing and exporting. Finally, Microsoft Jet included a new expression service provided by Visual Basic for Applications.