Abstract: Systems, methods and articles of manufacture are disclosed for generating a relational database query from an online analytical processing (OLAP) query against a cube. The cube may have dimensions, each dimension having a hierarchy of members. A level of the hierarchy of a dimension of the cube may be identified from which the OLAP query accesses a number of members exceeding a predefined threshold count of members. A relational database query may be generated that includes a predicate for at least one member from at least one level above the identified level in the hierarchy, instead of a plurality of predicates for members from the identified level. The relational database query may be generated from the OLAP query, from a definition for the hierarchy, and from the accessed members from the identified level. As a result, the relational database query may include fewer predicates and may be executed more efficiently.

Abstract: Disclosed are an apparatus, system, and method for generating a post-order set of members referenced by an MDX query statement invoking a post-order function. The apparatus includes an input module that receives the MDX expression specifying the relevant data set. A pre-order module generates a set of the members in pre-order organization. An initialization module generates an empty post-order set and inserts the first member of the pre-order set into the post-order set. An ancestor module determines whether the next member in the pre-order set has an ancestor in the post-order set and the location of the closest ancestor of the member if it exists. An insertion module then inserts the member immediately before the closest ancestor if the ancestor exists, or puts it in the rightmost position of the post-order set if an ancestor does not exist. An iteration module invokes the ancestor and insertion modules for each member of the pre-order set until the post-order set is filled.

Abstract: Systems, methods and articles of manufacture are disclosed for generating a relational database query from an online analytical processing (OLAP) query against a cube. The cube may have dimensions, each dimension having a hierarchy of members. A level of the hierarchy of a dimension of the cube may be identified from which the OLAP query accesses a number of members exceeding a predefined threshold count of members. A relational database query may be generated that includes a predicate for at least one member from at least one level above the identified level in the hierarchy, instead of a plurality of predicates for members from the identified level. The relational database query may be generated from the OLAP query, from a definition for the hierarchy, and from the accessed members from the identified level. As a result, the relational database query may include fewer predicates and may be executed more efficiently.

Abstract: Disclosed are an apparatus, system, and method for generating a post-order set of members referenced by an MDX query statement invoking a post-order function. The apparatus includes an input module that receives the MDX expression specifying the relevant data set. A pre-order module generates a set of the members in pre-order organization. An initialization module generates an empty post-order set and inserts the first member of the pre-order set into the post-order set. An ancestor module determines whether the next member in the pre-order set has an ancestor in the post-order set and the location of the closest ancestor of the member if it exists. An insertion module then inserts the member immediately before the closest ancestor if the ancestor exists, or puts it in the rightmost position of the post-order set if an ancestor does not exist. An iteration module invokes the ancestor and insertion modules for each member of the pre-order set until the post-order set is filled.

Abstract: Technique are provided for maintaining pre-computed aggregate views. A pre-computed aggregate view derived from one or more base tables is received, the pre-computed aggregate view including a pre-computed aggregate table and a view definition, the view definition including aggregate functions that can be any combination of sum, sum distinct, count(*), count, count distinct, min, and max, the view definition further including expressions that may be nullable. Changes to the one or more base tables are received, the changes being represented as insertions and deletions and being non-minimal. A set of incremental modifications to the pre-computed aggregate table are derived and applied based on the changes to the one or more base tables, wherein modifications may include any combination of inserts, deletes, and updates.

Abstract: Technique are provided for maintaining pre-computed aggregate views. A pre-computed aggregate view derived from one or more base tables is received, the pre-computed aggregate view including a pre-computed aggregate table and a view definition, the view definition including aggregate functions that can be any combination of sum, sum distinct, count(*), count, count distinct, min, and max, the view definition further including expressions that may be nullable. Changes to the one or more base tables are received, the changes being represented as insertions and deletions and being non-minimal. A set of incremental modifications to the pre-computed aggregate table are derived and applied based on the changes to the one or more base tables, wherein modifications may include any combination of inserts, deletes, and updates.

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: 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: 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.