Abstract: Two input binary signals are sampled in preparation for being encoded into one signal. The encoded signal is provided with one of the three discrete states based on the sample binary states of the two input signals. A first discrete state is provided if the sampled binary state of the first input signal is a first of two binary states. A second discrete state is provided if the sampled binary state of the first input signal is a second of two binary states, and if two sampled binary states of the second input signal are the same. A third discrete state is provided if the sampled binary state of the first input signal is a second of two binary states, and of the two sampled binary states of the second input signal are different. A corresponding decoding method is also described.

Abstract: A method, apparatus, and article of manufacture for a computer implemented authorization system. A statement is to be executed by a computer to manipulate data in a database stored on a data storage device connected to the computer. Initially, an environment of the database from which the statement was invoked is identified. Additionally, a security option is identified. Then, authorization privileges for the statement are determined based on the identified environment and security option.

Abstract: A method, apparatus, and article of manufacture for a computer-implemented technique for query optimization with deferred updates and autonomous sources. An object-oriented query is executed to retrieve data from a database. The database is stored on a data storage device connected to a computer. The object-oriented query is transformed into subqueries, wherein at least one subquery is directed against a database, and wherein one subquery is directed against an object cache. Each subquery that is directed against a database is executed to retrieve data from the database into the object cache. The subquery that is directed against the object cache is executed to retrieve data for the query, wherein the data incorporates updates to the object cache and updates to the database.

Abstract: A method, apparatus, and article of manufacture for a computer implemented groupby aggregation system. Groupby aggregation is performed when a statement is executed in a database stored on a data storage device, which is connected to a computer. Initially, data elements are input into a tournament tree from an input sequence. Then, a winner of a tournament in the tournament tree is identified. The winner is recycled into the tournament tree.

Abstract: The present invention discloses a method, apparatus, and article of manufacture for monitoring performance of a parallel database in a computer. In accordance with the present invention, the parallel database is stored on a data storage device in the computer. Groups of database nodes are identified. Collection time periods for collecting performance statistics from the identified group of database nodes are determined. Performance statistics are periodically collected from a subset of each identified group of nodes during the collection time periods. The collected performance statistics are stored in a memory connected to the computer and re-used when collecting performance statistics from one or more groups of database nodes in a succeeding collection time period.

Abstract: A method, apparatus, and article of manufacture for a computer-implemented model for user-defined search in Relational Database Management Systems. A statement is executed in a database stored on a data storage device connected to a computer. Data that is qualified by user-defined functions is located based on a model that supports user-defined search.