A method of processing database requests, the method comprising: obtaining access to a database with a plurality of data sets, wherein the data sets comprise data items of one or more data categories and wherein the data items of at least one data category are interrelated in a hierarchical structure in accordance with parent/child relationships, wherein the hierarchical structure exists in parallel to the data sets, wherein each data set includes one or more of the data items organized in the hierarchical structure, and wherein the hierarchical structure includes a plurality of references to the data items organized in the hierarchical structure and hierarchy information of the data items organized in the hierarchical structure; maintaining a positive buffer comprising data sets that have been retrieved in response to earlier database queries; maintaining a negative buffer with entries indicating data sets not included in the database, wherein maintaining the negative buffer comprises continuously updating the negative buffer based on at least one of the results of database queries and the results of earlier database queries, and aging-out older entries; receiving a database request that comprises at least one search parameter specifying a data item belonging to the hierarchical structure, the database request being directed at retrieving the most specific data set from the database, the most specific data set being either a data set exactly matching the database request or a data set that comprises at least one data item that is a parent of the at least one data item specified in the database request, wherein the negative buffer comprises for at least one entry included therein a reference to at least one data set in the positive buffer, the at least one data set being the most specific data set relative to the data item specified in the database request; and determining the most specific data set starting with the specified data item by consulting the positive buffer; if it is determined that the positive buffer does not include any matching data set: traversing the hierarchical structure in one or more traversing steps, wherein at least one of the traversing steps comprises consulting the negative buffer and jumping directly to a corresponding entry in the positive buffer and reading a referenced data set from the positive buffer to eliminate unnecessary traversing steps ahead, wherein eliminating unnecessary traversing steps ahead comprises skipping at least one parent of the determined data item during the traversing based on determining that the referenced data set in the positive buffer represents the most specific data set among the at least one skipped parent. obtaining access to a database with a plurality of data sets, wherein the data sets comprise data items of one or more data categories and wherein the data items of at least one data category are interrelated in a hierarchical structure in accordance with parent/child relationships, wherein the hierarchical structure exists in parallel to the data sets, wherein each data set includes one or more of the data items organized in the hierarchical structure, and wherein the hierarchical structure includes a plurality of references to the data items organized in the hierarchical structure and hierarchy information of the data items organized in the hierarchical structure; maintaining a positive buffer comprising data sets that have been retrieved in response to earlier database queries; maintaining a negative buffer with entries indicating data sets not included in the database, wherein maintaining the negative buffer comprises continuously updating the negative buffer based on at least one of the results of database queries and the results of earlier database queries, and aging-out older entries; receiving a database request that comprises at least one search parameter specifying a data item belonging to the hierarchical structure, the database request being directed at retrieving the most specific data set from the database, the most specific data set being either a data set exactly matching the database request or a data set that comprises at least one data item that is a parent of the at least one data item specified in the database request, wherein the negative buffer comprises for at least one entry included therein a reference to at least one data set in the positive buffer, the at least one data set being the most specific data set relative to the data item specified in the database request; and determining the most specific data set starting with the specified data item by consulting the positive buffer;