摘要:
A method, apparatus, system, and signal-bearing medium that in an embodiment track a history of statements that query data from a database. When a new statement is received, the history is searched for a correlation between the new statement and previous statements. The correlation is based on host variables in the history and the new statement. When a correlation is found, a prediction is made for the next statement to be received based on the previous statement in the history for which the correlation was found. The prediction is then used to retrieve pages from the database into a cache, which may be used by a subsequent statement.
摘要:
Methods, systems, and computer program products for dynamically adjusting computer resources, as appropriate, in response to predictions of query runtimes as well as for rendering costs of the computer resources actually utilized, which costs are consistent with consumer demands.
摘要:
A query access plan for executing a database query is dynamically selected from among multiple alternative query access plans based on the availability of computer resources allocated for running the query. Preferably, a first query access plan is generated based on resources then available, and if it is possible to provide additional resources, one or more alternative plans are generated based on the additional resources. If an alternative plan is significantly better than the original plan based on a comparison of query related parameters, the alternative is chosen for executing the query. Additional resources for running the query may be provided from logically partitioned and/or grid environments.
摘要:
An apparatus and method use ontological relationships in a query language and a computer database to improve database performance and utility. A set of ontological relationships are stored in the database and new query clauses are used to query the data in advantageous ways. Ontological relationships are preferably stored in a tree structure. This tree structure then can be used to reflect the ontological relationships of data stored in the columns of a database.
摘要:
A system, method and article of manufacture for identification of mergeable data in a data processing system and, more particularly, for providing mechanisms for facilitating identification of correlated columns from one or more database tables. One embodiment provides a computer-implemented method for managing storage of data having an associated measurement unit in a database table. The method includes storing the data in a column of the database table and generating units metadata describing the measurement unit. The units metadata is associated with the column of the database table.
摘要:
A method, system and article of manufacture for processing aggregation queries that are executed against a database and, more particularly, for managing aggregation data structures associated with tables of a database. One embodiment provides a method for managing creation of aggregation data structures for tables of a database. The method comprises receiving an aggregation query specifying at least one aggregation operation on data of a table of the database, determining aggregation information for the aggregation query, the aggregation information describing aspects of the aggregation query and its respective aggregation operation, determining whether the aggregation information satisfies predefined conditions, and, if the predefined conditions are satisfied by the aggregation information, creating an aggregation data structure for the table of the database in a manner allowing return of aggregation data of the created aggregation data structure upon receipt of a suitable aggregation query without executing the suitable aggregation query against the table of the database, wherein the suitable aggregation query includes the aggregation operation contained in the aggregation query for which the aggregation data structure was created.
摘要:
There are disclosed improved methods, systems, and computer program products for enhancing query optimization. More particularly, it relates to dynamically selecting alternative query access plans.
摘要:
A system, method and article of manufacture for identifying mergeable data in a data processing system and, more particularly, for identifying correlated columns from one or more database tables. One embodiment comprises determining correlation attributes for a first column and a second column from one or more database tables. The correlation attributes describe for each column at least one of the column and content of the column. The correlation attributes from the first and second column are compared and similarities between the first and second column are identified on the basis of the comparison. Then, on the basis of the identified similarities, it is determined whether the first and second columns are correlated. Only if the columns are determined to be correlated, the first and second columns are merged.
摘要:
Methods, articles of manufacture, and systems for providing access to a grid computing environment. In one environment, requests include resource specific criteria used to identify a particular grid resource to perform the request. In another embodiment, a request includes a queue criterion used to identify one of a plurality of queues on which the request is placed.
摘要:
A system, method and article of manufacture for query execution management in a data processing system and, more particularly, for optimizing execution of queries that are repeatedly executed against one or more databases in a data processing system. One embodiment provides a method for optimizing execution of a query that is repeatedly issued from an issuing entity against a database. The method comprises executing the query against the database to obtain an initial query result, returning the initial query result to the issuing entity, and managing re-execution of the query. Managing the re-execution comprises storing the initial query result in a temporary query result data structure, executing a trigger procedure for tracking database changes, when the trigger procedure detects a database change, updating the temporary query result data structure on the basis of the detected database change, and when the query is re-executed against the database, returning the temporary query result data structure to the issuing entity as query result.