Abstract: The invention describes a method for determining a storage location of a database object of a specific version, wherein indexes for each version of the database object are stored in a trie having a root node corresponding to the specific version, the method comprising: determining a trie corresponding to the specific version by accessing the root node of the trie corresponding to the specific version; determining an object identifier of the database object by traversing the trie corresponding to the specific version using a secondary key related to the database object as search key; determining the storage location of the database object by traversing the trie corresponding to the specific version using the determined object identifier as search key.

Abstract: The invention provides a time-efficient way of performing a query in a database or information retrieval system comprising operations such as intersection, union, difference and exclusive disjunction on two or more sets of keys stored in a database or information retrieval system. In a novel execution model, all data sources and operators are tries, and in input trie for a higher-order set operation can be the output of a lower-order set operation which is evaluated on demand. Two or more input tries are combined in accordance with the respective set operation, to obtain the set of keys associated with the nodes of a respective resulting trie. The physical algebra of the implementation of tries based on bitmaps corresponds directly to the logical algebra for the set operations and allows for efficient implementation by means of bitwise Boolean operations.

Abstract: The invention describes a method for determining a storage location of a database object of a specific version, wherein indexes for each version of the database object are stored in a trie having a root node corresponding to the specific version, the method comprising: determining a trie corresponding to the specific version by accessing the root node of the trie corresponding to the specific version; determining an object identifier of the database object by traversing the trie corresponding to the specific version using a secondary key related to the database object as search key; determining the storage location of the database object by traversing the trie corresponding to the specific version using the determined object identifier as search key.

Abstract: The invention provides a time-efficient way of performing a query in a database or information retrieval system comprising operations such as intersection, union, difference and exclusive disjunction on two or more sets of keys stored in a database or information retrieval system. In a novel execution model, all data sources are tries. Two or more input tries are combined in accordance with the respective set operation, to obtain the set of keys associated with the nodes of a respective resulting trie. An intersection operation performed in this way can be used for efficient range queries, in particular when two or more data items are involved in the query. The physical algebra of the implementation of tries based on bitmaps corresponds directly to the logical algebra for the set operations and allows for efficient implementation by means of bitwise Boolean operations.

Abstract: The invention describes a method for determining a storage location of a database object of a specific version, wherein indexes for each version of the database object are stored in a trie having a root node corresponding to the specific version, the method comprising: determining a trie corresponding to the specific version by accessing the root node of the trie corresponding to the specific version; determining an object identifier of the database object by traversing the trie corresponding to the specific version using a secondary key related to the database object as search key; determining the storage location of the database object by traversing the trie corresponding to the specific version using the determined object identifier as search key.