Abstract: A system and method for obtaining complete and correct answers from incomplete and/or partially incorrect databases determine if the answer to a query will be complete by determining whether the answer to the query is independent of an insertion update to the database. If the answer to the query is independent of an insertion update, the system and the method determine that the answer to the query will be complete. In the case of databases that may be incorrect, the system and the method determine if the answer to a given query will be correct by determining if the answer to the query is independent of a deletion update to the database. If the answer to the query is independent of a deletion update, the system and the method determine that the answer to the query will be correct.

Abstract: A method and apparatus for managing a web-site. An information definition query is received for defining an integrated view of non-uniform information retrieved from a multiple sources across a network, and stored in multiple formats. An integrated view is created according to the information definition query. A site definition query is received for defining a site view for the non-uniform information at the web-site. The site view is created according to the site definition query. The non-uniform information is then presented on the web-site, typically in the form of a HTML document.

Abstract: The present invention is a method and system for using materialized views to compute answers to SQL queries with grouping and aggregation. A query is evaluated a using a materialized view. The materialized view is semantically analyzed to determine whether the materialized view is usable in evaluating an input query. The semantic analysis includes determining that the materialized view does not project out any columns needed to evaluate the input query and determining that the view does not discard any tuple that satisfies a condition enforced in the input query. If the view is usable, the input query is rewritten to produce an output query that is multi-set equivalent to the input query and that specifies one or more occurrences of the materialized view as a source of information to be returned by the output query. The output query is then evaluated. The semantic analysis and rewriting may be iterated, with the output query of each iteration being the input query of the next iteration.

Abstract: A method of reducing the burden on database administrators when integrating information from a database system with a computer system over a computer network is disclosed. Rather than requiring the database administrator to express the meaning of database attribute names in a new language, the database administrators needs only to specify mappings between different database schemas by creating database example files. The database example files contain a common body of information values stored using the corresponding attribute names of the different database schemas. The database example files then become the basis for generation of a translation map between the computer system and the remote database system. Then, information queries from a user are translated with the translation map to the database schema of the remote database system.

Abstract: An improved information retrieval system user interface for retrieving information from a plurality of sources and for storing information source descriptions in a knowledge base. The user interface includes a hypertext browser and a knowledge base browser/editor. The hypertext browser allows a user to browse an unstructured information space through the use of interactive hypertext links. The knowledge base browser/editor displays a directed graph representing a generalization taxonomy of the knowledge base, with the nodes representing concepts and edges representing relationships between concepts. The system allows users to store information source descriptions in the knowledge base via graphical pointing means. By dragging an iconic representation of an information source from the hypertext browser to a node in the directed graph, the system will store an information source description object in the knowledge base.

Abstract: Query optimization which is done by making a graph of the query and moving predicates around in the graph so that they will be applied early in the optimized query generated from the graph. Predicates are first propagated up from child nodes of the graph to parent nodes and then down into different child nodes. After the predicates have been moved, redundant predicates are detected and removed. Predicates are moved through aggregation operations and new predicates are deduced from aggregation operations and from functional dependencies. The optimization is not dependent on join order and works where nodes of the graph cannot be merged.

Abstract: A query translator translates a query between a graphical user interface and a knowledge representation system. The knowledge representation system reformulates the query and generates an access plan to access data requested by the query. The access plan utilizes several different protocols to access the query information located in dissimilar databases distributed throughout a network. The knowledge representation system generates the access plan by first processing the query through a world view which defines the information in conceptual terms that a human being would understand and then processes the query through a system/network view which redefines the query into network and database access information so that the data requested by the query can be located.