OLE DB Programming Overview
OLE DB is a high-performance, COM-based database technology. It provides a common way to access data independent of the form in which it's stored. In a typical business situation, a vast amount of information is not stored in corporate databases. This information is found in file systems (such as FAT or NTFS), indexed-sequential files, personal databases (such as Access), spreadsheets (such as Excel), project planning applications (such as Project), and e-mail (such as Outlook). OLE DB enables you to access any kind of data store in the same manner, as long as the data store has an OLE DB provider.
OLE DB allows you to develop applications that access diverse data sources, whether they're DBMS or not. OLE DB makes universal access possible by using COM interfaces that support the appropriate DBMS functionality for a given data source. COM reduces unnecessary duplication of services and maximized interoperability not only among data sources but also among other applications.
Benefits of COM
This is where COM comes in. OLE DB is a set of COM interfaces. By accessing data through a uniform set of interfaces, you can organize a database into a matrix of cooperating components.
Based on the COM specification, OLE DB defines an extensible and maintainable collection of interfaces that factor and encapsulate consistent, reusable portions of DBMS functionality. These interfaces define the boundaries of DBMS components such as row containers, query processors, and transaction coordinators, which enable uniform transactional access to diverse information sources.