The description logic handbook
| Hi-index | 0.00 |
A method for constructing and maintaining a `semantic index'' using BACK, a system based on description logics, is described. A persistent index into a large number of objects is built by classifying the objects with respect to a set of indexing concepts and storing the resulting relation between object-ids and most specific indexing concepts on a file. The number of objects indexed is not limited by what BACK can hold in working memory, since the index files are incrementally updated. The index can be used for efficiently accessing the set of objects matching a query concept. The query is classified, and based on subsumption and disjointness reasoning with respect to indexing concepts instances are immediately categorized as hits, misses or candidates with respect to the query. Based on the index only, delayless feedback concerning the cardinality of the query (upper and lower bounds) can be provided during query editing.