MDAC 2.5 SDK - OLE DB Programmer's Reference
Chapter 11: Integrated Indexes

Next Fetch Position

With nonintegrated indexes, the next fetch position on the base table rowset was affected only by IRowset::GetNextRows and IRowset::RestartPosition. In a rowset with an integrated index, this can also be changed by IRowsetIndex::Seek. This is the same as the Seek functionality on separate index rowsets.