Abstract: Embodiments relate to aggregation operations. More specifically, embodiments relate to enforcing an aggregation constraint across a distributed network of compute nodes responding asynchronously. Each compute node individually processes the local partial aggregate value in parallel and asynchronously communicates with a conflict resolution node (CRN).

Abstract: Embodiments relate to aggregation operations. More specifically, embodiments relate to enforcing an aggregation constraint across a distributed network of compute nodes responding asynchronously. Each compute node individually processes the local partial aggregate value in parallel and asynchronously communicates with a conflict resolution node (CRN).

Abstract: A computer-implemented method for processing a transaction may include, upon receiving a transaction change request, operating a coordinator to generate a unique transaction identifier for the transaction request, send a data change request along with the unique transaction identifier to sources, and store the unique transaction identifier along with a respective first change count in a transaction status table. The method may also include, upon receiving a query, operating a given source to determine from the transaction status table, a second change count of sources associated with the unique transaction identifier, determine whether the second change count matches the first change count for each source, and when the first and second change counts match in each of the other sources, read data associated with the query from the given source and each source.

Abstract: A computer-implemented method for processing a transaction may include, upon receiving a transaction change request, operating a coordinator to generate a unique transaction identifier for the transaction request, send a data change request along with the unique transaction identifier to sources having respective source identifiers, and store the unique transaction identifier along with the respective source identifiers in a transaction status table. The computer-implemented method may further include, upon receiving a query, operating a given source to determine from the transaction status table, any other sources associated with the unique transaction identifier, determine whether the unique transaction identifier is in each of the other sources, and when the unique transaction identifier is in each of the other sources, read data associated with the query from the given source and each of the other sources.

Abstract: A computer-implemented method for processing a transaction may include, upon receiving a transaction change request, operating a coordinator to generate a unique transaction identifier for the transaction request, send a data change request along with the unique transaction identifier to sources, and store the unique transaction identifier along with a respective first change count in a transaction status table. The method may also include, upon receiving a query, operating a given source to determine from the transaction status table, a second change count of sources associated with the unique transaction identifier, determine whether the second change count matches the first change count for each source, and when the first and second change counts match in each of the other sources, read data associated with the query from the given source and each source.

Abstract: A computer-implemented method for processing a transaction may include, upon receiving a transaction change request, operating a coordinator to generate a unique transaction identifier for the transaction request, send a data change request along with the unique transaction identifier to sources having respective source identifiers, and store the unique transaction identifier along with the respective source identifiers in a transaction status table. The computer-implemented method may further include, upon receiving a query, operating a given source to determine from the transaction status table, any other sources associated with the unique transaction identifier, determine whether the unique transaction identifier is in each of the other sources, and when the unique transaction identifier is in each of the other sources, read data associated with the query from the given source and each of the other sources.

Abstract: A system for incrementally maintaining non-distributive aggregate functions in a relational database includes a data storage device in which a relational database is stored. A processor communicates with the data storage device and includes a database maintenance module. The database maintenance module includes a program for incrementally maintaining non-distributive aggregate functions in a relational database. The method embodied in the program includes determining whether all functions in a relational database query are distributive. Based on this determination, a basic propagate phase graph is selectively altered to yield a new propagate phase graph. Changes to an automatic summary table are then applied thereto based on the new propagate phase graph.

Abstract: A method, apparatus, and article of manufacture for incrementally maintaining a summary table derived from a plurality of base tables in a database stored on the computer. A plurality of modifications are applied to the base tables, and the applied modifications are then propagated to the summary table. The propagated modifications include an associated tag column containing a tag value, and the tag value indicates per row of the propagated modifications how many rows are to be added to or deleted from the summary table.

Abstract: A method, apparatus, and article of manufacture for the incremental maintenance of summary tables with complex grouping expressions where the change (insert/delete/update) of a single row of the base data can affect multiple rows in the summary table. The invention applies the complex grouping expression to the raw delta, yielding a delta stream consisting of multiple (but distinct) grouping combinations. The invention then inserts/deletes/updates delta values into/from the existing summary table so that each grouping combination of the delta stream modifies its corresponding grouping combination in the summary table.

Abstract: A system for incrementally maintaining non-distributive aggregate functions in a relational database includes a data storage device in which a relational database is stored. A processor communicates with the data storage device and includes a database maintenance module. The database maintenance module includes a program for incrementally maintaining non-distributive aggregate functions in a relational database. The method embodied in the program includes determining whether all functions in a relational database query are distributive. Based on this determination, a basic propagate phase graph is selectively altered to yield a new propagate phase graph. Changes to an automatic summary table are then applied thereto based on the new propagate phase graph.

Abstract: A method, apparatus, and article of manufacture for maintaining a materialized view derived from at least one base table in a database stored on a computer. An update is performed to the base table in a transaction. Thereafter, the materialized view is accessed to identify affected records therein using at least one mechanism, such as an isolation level or update- and exclusive-locks, to guarantee consistency while avoiding deadlocks with other transactions that modify at least one base table of the materialized view and to improve concurrency with other transactions that are accessing the materialized view when the modification to the base table is applied to the materialized view.

Abstract: A method, apparatus, and article of manufacture for the incremental maintenance of summary tables with complex grouping expressions.

Abstract: The invention provides method and apparatus for use in a database management system for managing a database containing data, where the database has storage for storing data in the database, and has an instruction processor for processing instructions for managing data stored in the database. The database has a constraint manager for managing constraints on said data stored in the database. The invention provides efficient method and means for deferred checking of data after bulk loading into said database for violation of constraints by determining an appropriate procedure for constraint checking by determining whether constraint checking is required; and if it is required, determining whether to implement full, or incremental checking for compliance with said constraints; and then checking the data in the database in accordance with the determined constraint checking procedure.

Abstract: A method, apparatus, and article of manufacture for optimizing database queries using a materialized view for a table referenced in the query, wherein the materialized view has different properties than the referenced table. The materialized view may be replicated across multiple processors of the computer system, so that some or all of the query can be executed in a local fashion wherein there is no data movement required to perform the operations. The materialized view also may be partitioned across multiple processors of the computer system using a different partitioning key than the referenced table. The materialized view may be a vertical and/or horizontal subset of the table, so that only selected columns and/or tuples from the table are present therein. Columns may be added to the materialized view to contain pre-computed results of complex expressions, and indices may be created on the columns of the materialized view.

Abstract: An automated methodology, and an apparatus for practicing the methodology, which enables the power and flexibility inherent in shared nothing parallel database systems (MPP) to be utilized on complex queries which have, heretofore, contained query elements requiring local computation or local coordination of data computation performed across the nodes of the distributed system. The present invention provides these features and advantages by identifying and marking the subgraphs containing these types of query elements as "no TQ zones" in the preparation phase prior to optimization. When the optimizer sees the markings, it builds a plan that will force the computation of the marked subgraphs to be in the same section. This preparation phase also provides the partitioning information for all inputs to the "no TQ zones". This allows the bottom-up optimizer to correctly plan the partitioning for the "no TQ zones".

Abstract: A method, apparatus, and article of manufacture for an intelligent compiler. A query is executed in a computer to retrieve data from a relational database stored on a data storage device. The query contains a procedural function. The query is compiled to generate an internal representation of the procedural function. Then, the execution of the procedural function is optimized using the generated internal representation.

Abstract: A method, apparatus, and article of manufacture for an intelligent compiler. A query is executed in a computer to retrieve data from a relational database stored on a data storage device. One or more scripting language statements are compiled to generate an internal representation. Then, the execution of the scripting language statements is optimized using the generated internal representation.

Abstract: An automated system for detecting and preventing mutating table violations of database integrity in a SQL query before generation and selection of an optimal query execution plan (QEP). This system modifies the query graph model (QGM) to restrict the choice of execution plans to those that avoid mutating table integrity (MTI) violations, thereby forcing database integrity during table mutation when executing the optimal QEP. Mutating table integrity violations are detected by evaluating the position in the QGM of each write-node referencing a particular base table with respect to each of the positions of all other read- and write-nodes referencing of the same base table. Every common-referencing node pair is tested for sequencing conflicts and a data-flow dam is inserted in the QGM where necessary or a poke query is inserted between the nodes to force the completion of the execution of one node before initiating execution of the other common-referencing node.

Abstract: In a relational database management system (RDMS), a method and system for constraint checking of bulk data after storage in a base table. This invention generates a "dummy" INSERT inquiry to cause the compiler constraint rule engine to generate code for checking for constraint violations. After construction of a Query Graph Model by the compiler, a logic module replaces the INSERT inquiry with a SELECT inquiry to create code that when executed will select records from the bulk data table. Constraint violations are handled in several ways by this invention, including merely reporting that a constraint error exists or listing those records that violate constraint conditions. The logic also enforces referential integrity constraints by applying the SQL CASCADE command to the violating records to expand the violation list to include children records that would be orphaned when their parent records are later removed.