MDAC 2.5 SDK - ODBC Programmer's Reference
Appendix F: ODBC Cursor Library
The cursor library implements SQLExtendedFetch by repeatedly calling SQLFetch in the driver.
The cursor library supports calling SQLExtendedFetch with a FetchOrientation of SQL_FETCH_BOOKMARK.
When the cursor library is used, calls to SQLExtendedFetch cannot be mixed with calls to either SQLFetchScroll or SQLFetch.