Patent application number | Description | Published |
20090100114 | Preserving a Query Plan Cache - A method, apparatus, and program product are provided for preserving a query plan cache on a backup system having a dataspace containing a copy of data and a copy of a query plan cache from a production system. An update is initiated of at least a portion of the copy of the data on the backup system with a portion of the data on the production system. A merge is initiated of updated query plans in the query plan cache from the production system with corresponding query plans in the copy of the query plan cache on the backup system. Objects are correlated in the updated query plans in the copy of the query plan cache with the updated copy of the data on the backup system. | 04-16-2009 |
20090164412 | Multiple Result Sets Generated from Single Pass Through a Dataspace - A method, apparatus and program product are provided for performing a query of a database. A database query is received, which includes first and second operations respectively configured to generate first and second disjoint results sets from a dataspace. The database query is analyzed to identify a set of attributes from the dataspace that are used by at least one of the first and second operations in the database query. During execution of the database query, a plurality of records from the dataspace is iteratively processed in a single pass, including, for each of the plurality of records, processing such record by retrieving the plurality of attributes for such record from the dataspace and performing each of the first and second operations on the record using the retrieved attributes for such record to build the first and second disjoint results sets. | 06-25-2009 |
20090248618 | Database Query Processing with Dynamically Activated Buffers - A method, apparatus and program product dynamically activate and/or deactivate buffers during execution of a database query. The dynamic deactivation and activation is based on the monitoring of information associated with the consumption of data by a plurality of threads during execution of an access plan for the database query. By doing so, the selection of a less optimal buffer position during optimization may be replaced with a more optimal buffer position during runtime, often resulting in improved query performance and parallelism. | 10-01-2009 |
20090276393 | Implementing Aggregation Combination Using Aggregate Depth Lists and Cube Aggregation Conversion to Rollup Aggregation for Optimizing Query Processing - A process combines multiple grouping sets into single rollup sets with depth lists defining the levels of grouping that must be performed. Grouping sets are identified that are contained within other sets and combined into single rollups with depth lists. Cube aggregation conversion to rollup aggregation is provided for optimizing database query processing. Natural sets of rollup hierarchies within a cube are recognized and the cube is converted into those rollup hierarchies. Once converted, the rollup aggregation is performed to significantly reduce required processing. | 11-05-2009 |
20090287638 | AUTONOMIC SYSTEM-WIDE SQL QUERY PERFORMANCE ADVISOR - A method, computer program product and computer system for providing SQL query performance advices to optimize SQL queries of a database, which includes providing a query cache to store records of optimized queries of the database, creating an event-driven web service, sending the records from the query cache to the web service, and analyzing the records using the web service to form SQL query performance advices. The method, computer program product and computer system can further includes outputting the SQL query performance advices to a viewer for display, or outputting the advices to a post-processing application for additional actions. | 11-19-2009 |
20100287206 | MAINTAINED SYMBOL TABLE ONLY INDEX - A method, apparatus and program product is provided for optimizing a database query. A query syntax, system generated predicates, and requisite statistics of the database query are analyzed to determine if a predicate structure is a good candidate for a symbol table only data structure. The predicate structure is analyzed to determine if the predicate structure is already encompassed by an encoded vector index. The symbol table only data structure is generated for at least one column in a database table without generating a corresponding vector data structure from an encoded vector index if the predicate structure is a good candidate and not encompassed by an encoded vector index. The symbol table only data structure is maintained by detecting a change in data associated with the symbol table only data structure and updating the symbol table only data structure to reflect the change in the data. | 11-11-2010 |
Patent application number | Description | Published |
20080215540 | OPTIMIZING A QUERY TO A PARTITIONED DATABASE TABLE USING A VIRTUAL MAINTAINED TEMPORARY INDEX THAT SPANS MULTIPLE DATABASE PARTITIONS - A query optimizer optimizes a query to a partitioned database table by determining common characteristics of the partitions and generating a virtual maintained temporary index that spans multiple partitions. Using the virtual maintained temporary index allows the query optimizer to generate an access plan based on the virtual maintained temporary index, which relieves the optimizer from having to individually optimize access to each partition for partitions that share common characteristics. | 09-04-2008 |
20080256024 | Portable and Iterative Re-Usable Suboptimization of Database Queries - A method, apparatus and program product to optimize a database query. A query plan is generated for the database query where the query plan includes first and second subplans. Cached optimization data associated with the first subplan and generated during evaluation of another query plan for a previous query that uses the first subplan is retrieved. The first subplan is evaluated for resource cost using the retrieved optimization data. The second subplan is also evaluated for resource cost. The query plan is then evaluated for resource cost based upon the evaluations of resource cost for the first and second subplans. A query plan is selected based on evaluations of resource cost and the plan is executed to generate a result set. | 10-16-2008 |
20080256025 | Database Query Optimization Utilizing Remote Statistics Collection - A method, apparatus and program product to optimize a database query. In a first system having a first dataspace, a query plan is generated for the database query. Remote statistics collection associated with the database query is initiated on a second system having a second dataspace. The remote statistics collection uses the second dataspace, which includes a current copy of at least a portion of the first dataspace on the first system. Database statistics are collected for the first system by analyzing the second dataspace and then communicating the collected database statistics to the first system for use in optimizing database queries executed by the first system. | 10-16-2008 |
20080301085 | Dynamic Database File Column Statistics for Arbitrary Union Combination - Embodiments of the invention provide techniques for generating database statistics for optimizing union queries. In general, working sets including samples of values in database columns are persistently maintained in a database. To optimize a union query, the working sets describing the columns included in the union query are combined to generate an ad hoc working set. The ad hoc working set is then used to generate a database statistic describing the combined columns. In another embodiment, working sets may also be maintained for generating statistics for optimizing non-union queries, thus enabling statistics to be refreshed more frequently. | 12-04-2008 |
20090077013 | METHODS, SYSTEMS, AND COMPUTER PROGRAM PRODUCTS FOR USER-DRIVEN TARGETED QUERY RE-OPTIMIZATIONS USING DELTA VALUES - A method, system, and computer program product for user-driven targeted query re-optimizations using delta values are provided. The method includes displaying a query tree for a query via a graphical user interface (GUI), where the query tree includes a plurality of interconnected nodes in a tree structure, and outputting a delta value as a difference between an estimated and an actual performance metric of query execution. The method also includes receiving a request to provide alternative execution plans for a subtree of a selected node of the query tree, and displaying at least one alternative execution plan description for the subtree of the selected node. The method further includes receiving a re-optimization request for a user selected alternative execution plan description, and displaying a re-optimized query tree resulting from the re-optimization request. | 03-19-2009 |
20090276394 | OBTAINING A PLAN FOR EXECUTING A QUERY IN A RELATIONAL DATABASE - A plan for executing a query in a relational database is obtained. A query for accessing data in the relational database is received. The query specifies N tables in the relational database from which data is to be retrieved. A determination is made whether a syntax of the query matches a syntax of a plan in a plan cache for executing the query. Matches are identified between generic table formats of the N tables specified in the query to generic table formats of N tables specified in the plan responsive to the syntax of the query matching the syntax of a plan in the plan cache for executing the query. The plan for executing the query is obtained based on whether the syntax of the query matches the syntax of the plan and based on identified matches between the generic table formats of the N tables specified in the query to the generic table formats of the N tables specified in the plan. | 11-05-2009 |