1. A method for indexing, in a relational system, a plurality of items that belong to a hierarchy, the method comprising the steps of: storing in an index a first index entry for a first item of the plurality of items, said first item being a child of a second item in said hierarchy; and storing in the index a second index entry for the second item of the plurality of items, said index entry containing a link to said first index entry for locating said first index entry in said index.