Abstract: Methods and apparatus implementing a technique for incrementally maintaining pre-computed aggregate views. In general, the technique includes: receiving a pre-computed aggregate view derived from one or more base tables. The pre-computed aggregate view including a pre-computed aggregate table and a view definition. The view definition including aggregation functions that can be any combination of sum, sum distinct, count(*), count distinct, min, and max. The view definition further including expressions that may be nullable. The technique includes receiving changes to the base table, the changes being non-minimal. The technique includes analyzing the view definition, including the type of aggregation functions and the nullability and data type of columns and expressions in the view definition, to reduce or eliminate the use of information in base tables in order to define the incremental modifications to the pre-computed aggregate table.

Abstract: Server-integrated methods and apparatus for processing precomputed views for answering user queries on a database are described. In accordance with one embodiment, a system for answering user queries on a database stored on a server includes a query processing system integrated into the server and configured to respond to user queries, and a query processing system integrated into the server and configured to process precomputed results of user queries on the database. In another aspect, a method of answering user queries on a database stored on a server includes responding to user queries received at the server, and processing, at the server, precomputed results of user queries on the database.

Abstract: Methods and apparatus for processing precomputed views for answering user queries on a database are described. In accordance with one aspect, a user database query on precomputation strategy effectiveness is responded to by defining, based upon user database query history, an analysis space consisting of a subset of all possible views for the database, and by characterizing the views in the analysis space. In accordance with a second aspect, a structure is imposed on an analysis space consisting of a subset of all possible views for the database based upon the capabilities of a query rewriting facility, and the views in the analysis space are characterized. In accordance with a third aspect, an analysis space consisting of a subset of all possible views for the database is defined, and a cost formula is applied to the analysis space based upon a user-defined subset of the data contained in the database.

Abstract: The invention features methods and apparatus for processing precomputed views for answering user queries on a database. In accordance with one aspect, a user query on the database is analyzed, and a candidate view based upon the user query is generated.

Abstract: Methods and apparatus implementing a technique for incrementally maintaining pre-computed aggregate views. In general, the technique includes: receiving a pre-computed aggregate view derived from one or more base tables. The pre-computed aggregate view including a pre-computed aggregate table and a view definition. The view definition including aggregation functions that can be any combination of sum, sum distinct, count(*), count distinct, min, and max. The view definition further including expressions that may be nullable. The technique includes receiving changes to the base table, the changes being non-minimal. The technique includes analyzing the view definition, including the type of aggregation functions and the nullability and data type of columns and expressions in the view definition, to reduce or eliminate the use of information in base tables in order to define the incremental modifications to the pre-computed aggregate table.

Abstract: Server-integrated methods and apparatus for processing precomputed views for answering user queries on a database are described. In accordance with one embodiment, a system for answering user queries on a database stored on a server includes a query processing system integrated into the server and configured to respond to user queries, and a query processing system integrated into the server and configured to process precomputed results of user queries on the database. In another aspect, a method of answering user queries on a database stored on a server includes responding to user queries received at the server, and processing, at the server, precomputed results of user queries on the database.

Abstract: A system and a method maintain a precomputed view corresponding to detail data in a database server by: determining a maintenance plan to refresh the precomputed view when detail data is changed; integrating the maintenance plan with a query execution plan in the database server; and executing the query execution plan.

Abstract: Methods and apparatus for processing precomputed views for answering user queries on a database are described. In accordance with one aspect, a user database query on precomputation strategy effectiveness is responded to by defining, based upon user database query history, an analysis space consisting of a subset of all possible views for the database, and by characterizing the views in the analysis space. In accordance with a second aspect, a structure is imposed on an analysis space consisting of a subset of all possible views for the database based upon the capabilities of a query rewriting facility, and the views in the analysis space are characterized. In accordance with a third aspect, an analysis space consisting of a subset of all possible views for the database is defined, and a cost formula is applied to the analysis space based upon a user-defined subset of the data contained in the database.

Abstract: A system and method for answering a relational database query is presented. According to an embodiment of the present invention, a database query is received. It is then determined whether that query can be rewritten in such a manner as to be able to utilize a precomputed view, such that an answer to the rewritten query is equivalent to an answer to the original query. If the query can be rewritten, it is determined whether the rewritten query can more efficiently derive the answer than the original query. The query which has the most efficiently derived answer is the query which is utilized to derive that answer.

Abstract: A data gathering system includes a plurality of remote units which are controlled from a central location. Each of the remote units is attached to a television receiver which is generally but not necessarily attached to a cable system. Each of the remote units can function to determine which of several TV modes is in use as well as to store TV channel selector data, data from an optical input device, and/or data input by viewers representative of the composition of the viewing audience. The data is stored for either later collection by a portable data collector, or for direct transmission via telephone to the central location. A video message for a TV viewer, such as a survey, may be transmitted from the central location and stored at the remote units, for later display on the TV receiver associated with the remote units. Substitution of alternate programming information may also be achieved by the central control point on selected of the remote units.

Abstract: A data gathering system includes a plurality of remote units which are controlled from a central location. Each of the remote units is attached to a television receiver which is generally but not necessarily attached to a cable system. Each of the remote units can function to determine which of several TV modes is in use as well as to store TV channel selector data, data from an optical input device, and/or data input by viewers representative of the composition of the viewing audience. The data is stored for either later collection by a portable data collector, or for direct transmission to the central location. A video message for a TV viewer, such as a survey, may be transmitted from the central location and stored at the remote units, for later display on the TV receiver associated with the remote units. Substitution of alternate programming information may also be achieved by the central control point on selected of the remote units.

Abstract: A data gathering system includes a plurality of remote units which are controlled from a central location. Each of the remote units is attached to a television receiver which is generally but not necessarily attached to a cable system. Each of the remote units functions to determine which of several TV modes is in use as well as to store TV channel selector data and data from an optical input device. All this data is stored for later transmission by each of the remote units to a central data collecting point. A video message for a TV viewer, such as a survey, may be transmitted from the central location and stored at the remote units, for later display on the TV receiver associated with the remote units. Substitution of alternate programming information may also be achieved by the central control point on selected of the remote units.