MDAC

Microsoft Data Access Components (MDAC) comprise the technologies that make UDA work. These technologies provide the basic framework for general-purpose data access in Microsoft Windows operating systems.

In designing MDAC, Microsoft set a number of guiding project goals, including the following:

Meet key customer requirements: performance, reliability, strongly committed vendors, and broad industry support.
Enable access to the broadest possible range of data stores, focusing on those that are most important to customers now and in the future. To address this goal, Microsoft took a three-pronged approach:
- Provide the best possible reuse of existing ODBC drivers, so organizations can continue to leverage their investments in these technologies. Continue to enhance strategic ODBC drivers from Microsoft as OLE DB components become broadly available.
- Build OLE DB providers for the most important Microsoft and non-Microsoft data stores.
- Create a comprehensive strategy for enabling the rapid development of high-quality, high-performance third-party OLE DB components to expose all mainstream data stores now and in the future.
Provide a migration path that will enable customers to leverage their investments in and experience with Data Access Objects (DAO), Remote Data Objects (RDO), and ODBC.

There are three primary technologies in MDAC. Microsoft ActiveX Data Objects (ADO) is a high-level, easy-to-use interface to OLE DB. OLE DB is the low-level, high-performance interface to a variety of data stores. ADO and OLE DB can both work with relational (tabular) and nonrelational (hierarchical or stream) data. Open Database Connectivity (ODBC) is another low-level high-performance interface that is designed specifically for relational data stores. These technologies work together to provide access to a diverse collection of data stores throughout the enterprise.

MDAC is an integrated part of the Windows® 2000 operating system. The MDAC SDK can be found within the Platform SDK. The Microsoft Data Access Components redistribution in English and 18 other languages is available for download on the Microsoft Universal Data Access Web Site.

Note To update Windows 95, Windows 98, and Windows NT® 4.0 without upgrading to Windows 2000 or installing the MDAC SDK, the redistributable setup program Mdac_typ.exe is available within the MDAC SDK and as a separate download on the aforementioned Web site. This program installs all of the files that your applications need to use the technologies in MDAC. The redistributable program does not offer an option to selectively install components; it installs all of them together or none at all. This way, all of the components are installed in the same configuration they were tested in before leaving Microsoft, which decreases problems with mismatched versions of DLLs.