Microsoft® Data Access Components (MDAC) provides easy-to-use, programmatic access to all types of data throughout the enterprise. Data-driven client/server applications deployed over the Web or a LAN can use these components to easily integrate information from a variety of sources, both relational (SQL) and non-relational. Microsoft Data Access Components consist of ActiveX™ Data Objects (ADO) and the Remote Data Service (RDS), the Microsoft OLE DB Provider for ODBC, Open Database Connectivity (ODBC), and ODBC drivers for Microsoft SQL Server, Microsoft Access and other desktop databases, and Oracle databases. All of these components are released, documented, and supported together.
Microsoft Data Access Components includes the following:
ActiveX Data Objects (ADO) enables you to write an application to access and manipulate data in a database server through an OLE DB provider. ADO's primary benefits are ease of use, high speed, low memory overhead, and a small disk footprint. ADO supports key features for building client/server and web-based applications.
ADO also features the Remote Data Service (RDS), a high-performance client-side data caching technology that brings database connectivity to Web-based applications. You can use Remote Data Service to build intelligent Web applications that let you access and update data from any OLE DB provider, including ODBC-compliant database management systems (DBMS). Because you can implement RDS with familiar technology — off-the-shelf visual controls, HTML, and Microsoft Visual Basic®, Scripting Edition (VBScript) — Remote Data Service integrates seamlessly with existing Visual Basic applications, letting you transport them to the Web.
MDAC includes Open Database Connectivity (ODBC) and the Microsoft OLE DB Provider for ODBC. Used in conjunction with an appropriate ODBC driver (see the following list), these components provide access to several popular database management systems, including Microsoft SQL Server, Microsoft Access and several other desktop databases, and Oracle.
The Microsoft OLE DB Provider for ODBC comprises a set of highly factored component interfaces for data access. It exposes OLE DB interfaces directly on top of ODBC drivers by replacing the ODBC Driver Manager for OLE DB consumers. Like ADO, the OLE DB Provider for ODBC is free-threaded to allow the sharing of objects in ISAPI applications.
The Microsoft ODBC 3.5 Driver Manager is a library that manages communication between applications and ODBC drivers. On Windows platforms, the Driver Manager is a dynamic-link library (DLL) that is written by Microsoft and can be redistributed by users of the Microsoft ODBC Software Development Kit (SDK). The Driver Manager exists mainly as a convenience to application writers and solves a number of problems common to all applications, such as determining which driver to load based on a data source name, loading and unloading drivers, and calling functions in drivers.
Microsoft SQL Server is a scaleable, high performance relational database management system for Windows NT® Server-based systems. Designed to meet the requirements of distributed client/server computing, SQL Server reduces complexity for users, administrators, and developers. SQL Server provides easy to use graphical administration tools, tight integration with Windows NT security, heterogeneous replication, support for very large databases (VLDB) and data warehousing, and integration with BackOffice® and Internet Information Server.
The Microsoft SQL Server ODBC driver provides a native interface used by ODBC-based applications to access Microsoft SQL Server databases. The driver provides optimal application performance by using native SQL Server network protocols and by taking advantage of all available SQL Server features. When used with the Microsoft OLE DB Provider for ODBC, the driver also allows OLE DB-based applications such as ADO to access Microsoft SQL Server. The driver is a multi-threaded, thread-safe Win32® driver that supports both ODBC 2.x and ODBC 3.x applications and complies with Level 2 of the ODBC API.
The Microsoft Jet Database Engine is a multi-user, file system based DBMS engine. Microsoft Jet provides the user with data storage, data manipulation, data retrieval (through SQL), security and database replication. Microsoft Jet is sometimes referred to as the "Access database" because it is the database engine provided in the Microsoft Access product.
The ODBC driver for Access databases allows applications to create and modify data in Microsoft Access databases. This driver may be used with OLE DB-enabled applications, Remote Data Objects (RDO), and ADO. It may be used with ADO applications when used in conjunction with the Microsoft OLE DB Provider for ODBC.
The Oracle ODBC Driver allows you to connect your ODBC-compliant application to an Oracle database. This version adds additional performance and control features, including access to PL/SQL packages, XA/DTC integration, and Oracle access from within Internet Information Server (IIS). The ODBC driver conforms to the ODBC specification described in the ODBC Programmer's Reference (Version 2.0) for your platform.