Abstract: A method of integrating a distributed ledger represented by a blockchain with a distributed storage network (DSN) begins by sending a proof of existence request to the DSN, the proof of existence request including an object name, an object version, a start time and an end time. The method continues by reading the object metadata for the sent object name. The method continues by checking a revision history from object metadata associated with the sent object name to ensure the object existed by the start time through the end time with no deletions and, if the object did not exist by the start time through the end time with no deletions, rejecting the proof of existence request and returning an error response. If the object did exist by the start time on through the end time with no deletions, the method continues by producing and returning an attestation comprising verification information related to the object.

Abstract: A method of integrating a distributed ledger represented by a blockchain with a distributed storage network (DSN) begins by sending a proof of existence request to the DSN, the proof of existence request including an object name, an object version, a start time and an end time. The method continues by reading the object metadata for the sent object name. The method continues by checking a revision history from object metadata associated with the sent object name to ensure the object existed by the start time through the end time with no deletions and, if the object did not exist by the start time through the end time with no deletions, rejecting the proof of existence request and returning an error response. If the object did exist by the start time on through the end time with no deletions, the method continues by producing and returning an attestation comprising verification information related to the object.

Abstract: A method for using pre-computed information stored in auxiliary structures to speed up processing of expensive queries on hierarchical documents such as XML documents being queried using XPath. The invention defines a taxonomy of such structures such as indexes and materialized views for storing pre-computed XPath results (PXRs), determines what portion of the query can be evaluated by the structures, and computes the compensation for the results generated by the structures. The invention detects all structures applicable to the query and rewrites the query to use such structures, speeding up the performance of the queries. The invention identifies the matching structures by detecting containment mappings between XPath expressions in the query and the structure. The invention also includes a new representation for XPath expressions that is rich enough to express all features of XPath.

Abstract: A method, apparatus, and article of manufacture for optimizing database queries using an automatic summary table. A query is analyzed using matching and compensation tests between the query at least one correlated subquery within the query and the automatic summary table to determine whether expressions occurring in the query, but not in the automatic summary table, can be derived using the automatic summary table. If so, the query is rewritten so that the automatic summary table is used.

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 optimizing database queries using a derived summary table, wherein a definition of the summary table is based on a full select statement, including, but not limited to, a derived table involving nested GROUP BY operations and complex HAVING clauses with subqueries or joins, that is materialized in the table and describes how the summary table was derived. A query is analyzed using matching/compensation tests between the query and the definition of the summary table (that is, a query by itself) to determine whether expressions occurring anywhere in the query, but not in the summary table, can be derived using either the content in the summary table alone, or after combining (through some relational operator) the content of the summary table with other base tables, and hence the query is subsumed by or overlaps with the summary table definition.

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: A method, apparatus, and article of manufacture for optimizing database queries using an automatic summary table. A query is analyzed using matching and compensation tests between the query at least one correlated subquery within the query and the automatic summary table to determine whether expressions occurring in the query, but not in the automatic summary table, can be derived using the automatic summary table. If so, the query is rewritten so that the automatic summary table is used.

Abstract: A method, apparatus, and article of manufacture for optimizing database queries using subsumption tests between the query and at least one summary table that comprises a cube index to determine whether an expression in the query can be subsumed in the summary table. The summary table stores at least one materialized view involving at least one GROUP BY operation that computes at least one of the following: (1) a cube, (2) a rollup, (3) a grouping set, and (4) a concatenation of cubes, rollups, grouping sets, and one or more grouping items. When the expression in the query can be subsumed in the summary table, the query is rewritten to use the summary table.

Abstract: A method and system for refreshing materialized join views includes asynchronously evaluating changes to the base tables, i.e., evaluating changes for an intended time tintended at an evaluation time teval that is later than the intended time. Changes made to the base table between the intended time tintended and evaluation time teval are recursively compensated for. The results of the evaluating and compensating are then applied to the materialized view to refresh the view.

Abstract: A system, method, and article of manufacture for supporting summary tables in a database system that does not otherwise support summary tables is disclosed. The system generally comprises a central program and one or more database systems that may be heterogeneous. At least one of the database systems does not support the generation, maintenance, and/or querying of summary tables. The central program is configured to communicate with the database systems and to identify relations corresponding to summary tables (also referred to as materialized views) within one or more of the database systems. The central program may initiate the generation of summary tables, which may be populated local to the central program or local to one or more of the database systems. The central program may also maintain or coordinate maintenance of the summary tables.

Abstract: A system, method, and article of manufacture for supporting summary tables in a distributed database environment is disclosed. The system generally comprises a central program and a plurality of remote database systems that may be heterogeneous. The central program is configured to communicate with the database systems and to support summary tables (also referred to as materialized views) within the central program or within one or more of the database systems. The summary tables may contain summary data from one or more of the database systems. The central program may initiate the generation of summary tables, which may be populated local to the central program or local to one or more of the database systems. The central program may also maintain or coordinate maintenance of the summary tables.

Abstract: A method, apparatus, and article of manufacture for optimizing database queries uses a derived summary table, wherein a definition of the summary table is based on a full select statement that is materialized in the table and describes how the summary table was derived. The summary table definition can be a complex query involving nested GROUP BY operations as well as complex HAVING clauses with subqueries or join operations. A query is analyzed using subsumption tests between the query and the definition of the summary table to determine whether expressions occurring anywhere in the query, but not in the summary table, can be subsumed in the summary table. In performing the query, an expression in the query is subsumed in the summary table when the expression can be re-derived from one or more of the columns of the summary table.

Abstract: A method, apparatus, and article of manufacture for optimizing database queries using subsumption tests between the query and at least one summary table that comprises a cube index to determine whether an expression in the query can be subsumed in the summary table. The summary table stores at least one materialized view involving at least one GROUP BY operation the computes at least one of the following: (1) a cube, (2) a rollup, (3) a grouping set, and (4) a concatenation of cubes, rollups, grouping sets, and one or more grouping items. When the expression in the query can be subsumed in the summary table, the query is rewritten to use the summary table.

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.