Patent application number | Description | Published |
20080275841 | Self Tuning Database Retrieval Optimization Using Regression Functions - A system and method for accessing a relational database and estimating the selectivity of a query (e.g., an SQL query) in order to better predict the number of qualifying records for simple and complex queries. A dataset is created based upon queries applied against the database by the user community. The dataset is populated with information related to query conditions and their respective combinations. A regression function reflecting correlations between query conditions is generated and used as a data mining model to calculate table-specific estimates for the cardinality of subsequent queries. An appropriate access method is then selected from a set of available access methods based upon the number of estimated query-qualifying records. By periodically updating the regression model with FIFO managed queries, a self-tuning mechanism is achieved resulting in better selectivity/result size estimates for use in selecting access methods used in compiling subsequent SQL queries applied against the database. | 11-06-2008 |
20080306906 | SYSTEM FOR AGGREGATION SUBQUERY JOIN ELIMINATION - A system for use with an information retrieval system, in which system is used for transforming a database statement containing a first subquery and a second subquery joined together, the first subquery including a group by operation over a child subquery, the information retrieval system comprising means for removing the first subquery from the database statement thereby eliminating the join between the first subquery and the second subquery. | 12-11-2008 |
20090012990 | SYSTEM AND PROGRAM FOR JOINING SOURCE TABLE ROWS WITH TARGET TABLE ROWS - Disclosed is a data processing system, and an article of manufacturing for use with the data processing system. The data processing system joins rows associated with a column of a source table with rows associated with a column of a target table. The data processing system includes a source node containing the source table and including a target node containing the target table. The data processing system further includes a generating module for generating a reduced representation of selected rows associated with the column of the source table, and generating a representation of the column of the target table, a filtering module for filtering the generated reduced representation of selected rows associated with the column of the source table through the generated representation of the column of the target table, the filtered generated reduced representation of selected rows identifying source table rows that do not have to be joined with the target table, and a joining module for joining, to the rows associated with the column of the target table, the rows associated with the column of the source table minus the filtered generated reduced representation of selected rows. | 01-08-2009 |
20100057670 | APPARATUS AND SYSTEM FOR REDUCING LOCKING IN MATERIALIZED QUERY TABLES - Disclosed is an apparatus and system for reducing locking in materialized query tables (MQT) for distributive functions. The apparatus includes an insert module that inserts into an MQT table a child record when a new record is inserted into a base table associated with the MQT. The child record includes values associated with the insert operation. Also included is a delete module that inserts into the MQT a child record that includes measure values that are the negative of the measure values in the base table row that is the subject of the delete operation. An update module inserts two child rows into the MQT, one negating the affected record and the other adding the values of the update operation. Each inserted child row includes a unique identifier that relates the inserted row to a parent row. An execution module generates responses using the values indicated by the cumulative records in a family. | 03-04-2010 |
20130198164 | Executing CASE Expressions Containing Subqueries - Methods and apparatus, including computer program products, implementing and using techniques for executing a query in a computer to retrieve data from a relational database stored on a data storage device. A query is received that contains a CASE expression having one or more subqueries. A query execution plan is generated. The query execution plan uses a parameterized union all operator to keep the semantics of the CASE expression, and a nested loop join operator to drive data across the section of the query execution plan that executes the CASE expression without performing any join operations. The generated query execution plan is executed in the computer to retrieve data from the relational database. | 08-01-2013 |
20130198165 | GENERATING STATISTICAL VIEWS IN A DATABASE SYSTEM - Techniques are disclosed for generating statistical views in a database system. In one embodiment, a request is received to execute a database workload. One or more constraints pertaining to executing the database workload is retrieved. The database workload is evaluated to generate multiple statistical view candidates. The statistical view candidates are refined based on the one or more constraints. One or more statistical views are then generated based on the refined statistical view candidates. | 08-01-2013 |
20130226902 | SYSTEM AND PROGRAM FOR JOINING SOURCE TABLE ROWS WITH TARGET TABLE ROWS - A data processing system, and an article of manufacturing, join rows associated with a source table column with rows associated with a target table column. A source node and a target node contain the source and target tables, respectively. A reduced representation of selected rows associated with the source table column is generated, as is a representation of the target table column. A filtering module filters the generated reduced representation of selected rows associated with the source table column through the generated representation of the target table column, the filtered generated reduced representation of selected rows identifying source table rows that do not have to be joined with the target table. The rows associated with the source table column minus the filtered generated reduced representation of selected rows are joined to the rows associated with the target table column. | 08-29-2013 |
20140012835 | GENERATING STATISTICAL VIEWS IN A DATABASE SYSTEM - Techniques are disclosed for generating statistical views in a database system. In one embodiment, a request is received to execute a database workload. One or more constraints pertaining to executing the database workload is retrieved. The database workload is evaluated to generate multiple statistical view candidates. The statistical view candidates are refined based on the one or more constraints. One or more statistical views are then generated based on the refined statistical view candidates. | 01-09-2014 |