A set of mandatory interfaces is required to expose the minimal level of functionality supported by the data store. They can return data intact or perform operations on the data. Providers can be simple or complex, depending on the needs of the consumer. These providers manage folders and documents and are explained in Resource Rowsets and Document Source Providers. In addition to these two categories of providers, a special class of providers?called document source providers?was introduced in OLE DB 2.5. It is not dependent on other providers?service or data?to provide data to the consumer. A data provider owns its own data and exposes it in tabular form. The Cursor Service for OLE DB is an example of this. A service provider may also be further defined as a service component, which must work in conjunction with other service providers or components. It does not own its own data and, in reality, serves a dual role of consumer and provider. A service provider encapsulates a service by producing and consuming data through OLE DB interfaces. Providers fall into two categories: those providing services and those providing data. The application that uses OLE DB functionality is called the consumer*,* while the one that accesses the data by exposing OLE DB interfaces is called the provider. OLE DB architecture is built upon the precept of an application accessing diverse data stores through a small application built specifically for that purpose.
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