When you type data and retrieve attributes, the data-typing part of the process is the most expensive in terms of performance. You can type data in a second way that improves performance by separating the data-typing and attribute-retrieval functions. Use the following functions for intermediate data typing:
DtDtsBufferToDataType()
DtDtsFileToDataType()
DtDtsDataTypeToAttributeList()
DtDtsDataTypeToAttributeValue()
Use these functions if your application queries for more than a single attribute value. When you use these functions, an object is typed and then that type is used to retrieve one or more attributes from the attribute list.
Using the intermediate data-typing functions is the recommended way to type data and retrieve attributes. These functions call the advanced data-typing functions and make the same assumptions about buffers as the simpler data typing.