1. A computer-readable medium having an index, wherein: said index indexes a table that includes one or more fields; said index is arranged and ordered based on key values associated with at least one of said one or more fields; and said index contains a plurality of index entries, wherein each entry of said index entries: maps to at least one corresponding row in said table, and contains first access control data, this is not reflected in said key values, that defines user access privileges to access said at least one corresponding row.