Searching within elements of a hierarchically structured database. Each element may include one or more hierarchically structured nodes for defining attributes of the element. One or more nodes of the searched element may fulfill one or more search conditions (c.sub.0,c.sub.i, . . ).A plurality of codes may be searched and a unique identifier (EID) may be assigned to each of the selected nodes.A reference index may be created that allows to derive for each unique identifier (EID) of a selected node the corresponding element of the database.A set (L, E.sub.i) of unique identifiers may be retrieved for each of the one or more search conditions for ancestor nodes, which fulfill the respective search condition.A final set of unique identifiers may be obtained.The searched elements of the database may be retrieved based on the final set of unique identifiers and the reference index.