123 results about "Materialized view" patented technology

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.

A method is provided for incrementally refreshing a materialized view after multiple operations on a row of a base table of the materialized view, by determining an equivalent operation for the multiple operations and refreshing the materialized view according to the equivalent operation. The method is applicable to a materialized view based on multiple base tables on which multiple operations have been performed. The step of determining the equivalent operation can include identifying rows for which an earliest operation is a DELETE operation, or rows for which a latest operation is an INSERT operation, or a combination of the two. The step of refreshing the materialized view includes performing an inverse operation of the equivalent operation to determine a pre-update state of the row, and refreshing the materialized view based on the pre-update state. Additional embodiments are provided which enhance the performance of materialized view refresh queries.

The TABLE function mechanism available in a RDBMS is used to integrate RDF models into SQL queries. The table function invocation takes parameters including an RDF pattern, an RDF model, and an RDF rule base and returns result rows to the SQL query that contain RDF triples resulting from the application of the pattern to the triples of the model and the triples inferred by applying the rule base to the model. The RDBMS includes relational representations of the triples and the rules. Optimizations include indexes and materialized views of the representations of the triples, precomputed inferred triples, and a method associated with the TABLE function that rewrites the part of the SQL query that contains the TABLE function invocation as an equivalent SQL string. The latter technique is generally applicable to TABLE functions.

The invention herein provides method and apparatus, including software for determining a set of materialized views or indices of the contents or a subset of the contents of a database in a data processing system to be created for one or more users of the database. The method and apparatus provide method and means for evaluating a workload presented by a user to the database; evaluating the data processing system characteristics; evaluating the database characteristics; and, using the above evaluations for recommending a set of suitable materialized views or indices to the user. Another aspect of the invention, which may be used for a workload presented by a user of a database in a data processing system, provides method and apparatus, including software for determining a set of materialized views or indices of the contents or a subset of the contents of the database, by: generating a plurality of materialized view candidates from evaluation of the workload, data processing system characteristics and database characteristics; estimating statistics for the materialized view candidates such as the number of rows, row size, and column statistics; generating a plurality of potential index candidates by evaluating the workload, data processing system characteristics, database characteristics and the materialized view candidates; and, from the materialized view candidates and index candidates selecting a set of suitable materialized views and / or indices for submission to the user.

A method is provided for generating a materialized view recommendation for at least one back-end server that is connected to a front-end server in a heterogeneous, distributed database system that comprises parsing a workload of federated queries to generate a plurality of query fragments; invoking a materialized view advisor on each back-end server with the plurality of query fragments to generate a set of candidate materialized views for each of the plurality of query fragments; identifying a first set of subsets corresponding to all nonempty subsets of the set of candidate materialized views for each of the plurality of query fragments; identifying a second set of subsets corresponding to all subsets of the first set of subsets that are sorted according to a dominance relationship based upon a resource time for the at least one back-end server to provide results to the front-end server for each of the first set of subsets; and performing a cost-benefit analysis of each of the second set of subsets to determine a recommended subset of materialized views that minimizes a total resource time for running the workload against the at least one back-end server.

Techniques are provided for creating object-oriented materialized views. The object-oriented materialized views may be object materialized views or object-relational materialized views. The base tables may be object tables, object relational tables, or relational tables. The object-oriented materialized views may be refreshed, fully or incrementally. When an object-oriented materialized view is created, refresh code is generated for it. Through the use of object-oriented materialized views, users gain both the efficiency of materialized views and the power of the object-oriented paradigm.

Disclosed are system and methods for processing and storing data files, using a data edge file format. The data edge file separates information about what symbols are in a data file and information about the corresponding location of those symbols in the data file. An index for the data files can be generated according to the data edge file format. Using the data edge index, a materialized view of a result set can be generated in response to a search query for the source data objects stored in object storage.

Disclosed is an improved method and system for implementing DBMS server performance optimization. According to some approaches, the method and system incorporates DBMS wizards recommendations with analytical queuing network models for purpose of evaluating different alternatives and selecting the optimum performance management solution with a set of expectations, enhancing autonomic computing by generating periodic control measures which include recommendation to add or remove indexes and materialized views, change the level of concurrency, workloads priorities, improving the balance of the resource utilization, which provides a framework for a continuous process of the workload management by means of measuring the difference between the actual results and expected, understanding the cause of the difference, finding a new corrective solution and setting new expectations.

Techniques are provided for improving efficiency of database systems, and in particular, to refreshing materialized views maintained by database systems and rewriting queries to access the materialized views. According to the approaches, a ranked materialized view is incrementally refreshed, and during the incremental refresh operation, rows in the partitions of the materialized view are ranked within the partitions.

A technique for refreshing materialized views in a database is disclosed. The detail table is partitioned, and changes made to the detail table are tracked with information stored, for example. Only sections in the materialized view which correspond to the partitions which include modifications made to the detail table are refreshed, thus avoiding the need of a complete refresh to overcome staleness.

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. In addition, the central program may be configured to receive user queries on one or more of the database systems and to generate optimized query plans based upon the user queries, considering in so doing, the summary tables.

Techniques are provided for allowing the reorganization and / or redefinition of data in a relational database with minimal or no downtime by allowing “online” reorganization / redefinition of the data. According to one aspect of the invention, an empty revised table is created in the same schema as the target table. The revised table is created with the attributes that are desired for the reorganization / redefinition of the target table. Triggers, constraints, grants and indexes that are associated with the target table are replicated for the revised table. The reorganization / redefinition is performed by using an underlying mechanism that involves using incrementally maintainable materialized views.According to one feature, the revised table is initialized and periodically synchronized with the target table. After the reorganization and / or redefinition is complete on the revised table, the revised table and the target table switch identities such that the revised table is now the target table and the target table becomes the revised table.

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.

A heuristic approach is used to order materialized view (MW) candidates in a list based on descending order of their reduction power. A query (e.g., SQL query) is then matched with the MVs in the list order, wherein searching is stopped when matching has been found. The query is matched with materialized views in the ordered list by identifying a materialized view candidate as follows: identifying an MV that is not locked by a REFRESH process; identifying a matching MV that does not require a regroup; identifying a matching MV that does not require a rejoin; identifying a matching MV that does not require a residual join; or identifying an MV with largest reduction power from the list of candidates.

The disclosed embodiments relate to a system and method for refreshing a materialized view that is at least in part derived from a table. The system may be adapted to provide availability of the table and the materialized view while the materialized view is being refreshed. The system may include a refresh log that contains a plurality of entries, each of the plurality of entries corresponding to a change in the table, each of the plurality of entries comprising an epoch identifier. The system may also include a refresh manager that performs a refresh operation on the materialized view in multiple steps by (a) successively reading a first subset of the plurality of entries indicated by a specific epoch identifier from the refresh log, (b) identifying a second subset of the plurality of entries from within the first subset of the plurality of entries, the second subset of the plurality of entries falling within a primary key value boundary and (c) applying the second subset of the plurality of entries to the materialized view.

A computer readable storage medium includes executable instructions to define an interface to a multi-dimensional cube divided into partitions distributed across nodes supporting a shared nothing multi-dimensional distributed database. The interface includes a metadata module characterizing access paths to data within the multi-dimensional cube and an access path module to convert a data request into an access path protocol to retrieve data from the multi-dimensional cube to satisfy the data request.

Method and system for providing results for task list queries to Workflow Management Systems (WfMSs) and Human Task Management Systems (HTMSs). In one aspect, a method for providing the result of a task list query to a human task database includes caching data from the database in a plurality of materialized views. A new request for a list of tasks from the database is received, and a new query is created when the new request applies to the data in a particular materialized view. When the particular materialized view includes data that requires updating from more recent data in the database, the materialized view is so updated. The new query is executed against the data in the materialized view instead of executing the new query against the data in the database.

Described herein is a system for creating and maintaining materialized views. The maintenance of the materialized views is performed in a distributed manner that improves efficiency and performance in response to the queries for materialized views or views on top of the materialized views.

A method and apparatus for a data warehouse built on top of MapReduce is provided. A virtual view is defined on top of the common star or snowflake data warehouse schema. A SQL-like, but much more succinct, query language is provided to leverage the virtual view. Many advanced query processing features leveraging the virtual view are also provided. Further, several optimization techniques ranging from data compression and access method to multi-query optimization and exploiting materialized views are provided. Further, a technique to seamlessly integrate the data warehouse system into any ad-hoc MapReduce jobs is provided. Thus, fully leveraging the power of both MapReduce and data warehouse technologies is achieved.

The disclosed embodiments relate to a system and method for performing conflict resolution when refreshing a materialized view. The system may comprise a logging mechanism that maintains a refresh log, the refresh log may contain a first range and a second range that at least partially overlap, the first range and the second range each having a timestamp associated therewith. The system may also include a refresh manager that resolves conflicts between the first range and the second range that at least partially overlap by selecting portions of the first range and the second range that have the more recent timestamp and applying the selected portions of the first range and the second range to the materialized view. In another embodiment, the system may comprise a logging mechanism that maintains a refresh log, the refresh log containing a range and a single-row entry, the range and the single row entry each having a timestamp associated therewith. The system may also include a refresh manager that resolves conflicts between the range and the single-row entry by ignoring the single-row entry if the single-row entry is part of the range and if the single-row entry has the more recent timestamp and by applying the single-row entry to the materialized view if the single-row entry is not part of the range or if the range has the more recent timestamp.

The cost of running a query (having a query range) on a multidimensional database may be estimated using a process factors criteria beyond merely the number of affected records. First, a materialized view of the database may be represented as a container of tuples, sorted by key. Then keys may be stepped through, each key representing a mapping of a combination of tuples from the container. At each step, the process may request the next smallest key in the query range greater than or equal to the key of the current step, which results in the tuple in the database whose key is the smallest, greater than or equal to the requested key, and determine if the resulting tuple is in the query range. The cost of the query may then be estimated as the number of tuples upon which the range check was performed.

A method and system for enhancing a materialized view. In one embodiment the method includes analyzing a defined query of the materialized view, checking the requirements of the materialized view log, generating execution scripts that automatically create and enhance the materialized view logs and tuning the materialized view.

The invention relates to the database field, and provides a method and a system for optimizing system performance based on materialized view. The method comprises the following steps: capturing SQL (structure query language) query language; confirming a question base table formed by SQL query language which triggers system full scan; establishing a materialized view aiming to the question base table; optimizing the established materialized view; and processing corresponding SQL query utilizing optimized materialized view. The invention solves the inaccuracy problem caused by traditional manual refreshment of the materialized view in the prior art, and avoids the effect to the operation performance of the base table brought by manual synchronous refreshment. The regularly automatic refreshment technology provided by the invention works with index, so that the data is led to reach a relative good query state, and a user can quickly and accurately view the data.

Techniques are provided for improving efficiency of database systems, and in particular, to refreshing materialized views maintained by database systems and rewriting queries to access the materialized views. According to the approaches, a ranked materialized view is incrementally refreshed, and during the incremental refresh operation, rows in the partitions of the materialized view are ranked within the partitions.

A method and system for updating both partition change track tables and non-partition track tables in a materialized view. A log-based incremental refresh is performed on the materialized view and a partition change tracking based refresh is performed on the materialized view. The dependency of the materialized view log for the partition change track base table is removed.

A heuristic approach is used to order materialized view (MW) candidates in a list based on descending order of their reduction power. A query (e.g., SQL query) is then matched with the MVs in the list order, wherein searching is stopped as soon as good enough matching has been found. The query is matched with materialized views in the ordered list by identifying a materialized view candidate as follows: identifying an MV that is not locked by a REFRESH process; identifying a matching MV that does not require a regroup; identifying a matching MV that does not require a rejoin; identifying a matching MV that does not require a residual join; or identifying an MV with largest reduction power from the list of candidates.

A method for database multi-list union query comprises the steps of determining a plurality of lists associated with service logic in a relational database; connecting the database, and obtaining information of the plurality of lists; associating the plurality of lists into a materialized view list according to foreign key information; processing fields in the materialized view list, generating a combination key, and setting the combination key as a row key of a newly-built column type data table; establishing a mapping relation from the relational database to the column type data table, and writing the mapping relation and data records in the materialized view list into an XML file; mapping data in the materialized view list to the row key and a column identifier in the column type data table, writing the data records into the column type data table; performing multi-list query in the column type data table, and obtaining query results. According to the method, multi-list union query can be implemented quickly and efficiently under the condition of mass data.

The disclosed embodiments provide a system for managing a materialized view of data in a data store. During operation, the system obtains a first creation time of a first materialized view of the data in the data store. Next, the system verifies that the first materialized view is not affected by deletions applied to the data since the first creation time. The system then identifies one or more additions to the data that are not included in the first materialized view. Finally, the system applies the additions to the first materialized view to maintain an eventual consistency of the first materialized view with the data store.

A computer implemented system that facilitates view matching for outer join views comprises an interface component that receives at least one query that includes one or more outer join operators. A view matching-component converts the at least one query and outputs a substitute query expression. In accordance with one aspect of the subject invention, the view-matching component can comprise a normalization component that converts the at least one query and at least one materialized view into a normalized query expression and a normalized view expression. Furthermore, the view-matching component can include an analysis component that receives the normalized query expression and the normalized view expression, and a construction component that constructs the substitute query expression.