摘要:
The activity of a database is monitored, and index split options are dynamically determined from the monitored database activity. Appropriate action may then be taken based on the dynamically determined index split options. For example, the index may be automatically split using the dynamically determined index split options. A user command that specifies index split options may be compared to the dynamically determined index split options, and if the user command is not compatible with the dynamically determined index split options, the command may be inhibited, or the user may receive a warning message in response to the command. In addition, existing index use may be monitored, and if the monitored index use indicates the index is split poorly, the index may be re-generated using the dynamically determined index split options.
摘要:
A program product, an apparatus, and method of autonomically adjusting when performance data from a call stack is collected during a trace. In particular, the sampling interval between call stack collections may be autonomically adjusted while a trace is executing based upon the call stack, various performance metrics, and/or previous call stack collections.
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:
A master table and one or more slave tables are linked together by different referential integrity constraints. A database engine maintains a separate data structure that includes information about which slave tables include corresponding records that may be affected by a constraint. Accordingly, when an operation is performed on the master table, the data structure is referenced to determine which slave tables has records which are affected as well. The data structure may be a bitmap, an encoded vector index, or separate fields within the master database. As a result of this data structure, unnecessary I/O operations are avoided involving slave tables without a corresponding record.
摘要:
A method and apparatus for monitoring the performance of a computer system with one or more active programs. A periodic sampling of the call stack is obtained. The sampled call stack is examined to infer the system performance similar to that obtained using prior art event based profiling. Embodiments also are directed to a combination approach to describing the system performance using a historical sampling to infer additional detail to fill in the gaps of the sampled data.
摘要:
A method, system and article of manufacture for migration of databases and, more particularly, for optimizing migration of a database from a source system to a target system. One embodiment provides a computer-implemented method for optimizing migration of a database from a source system to a target system. The method comprises collecting source parameters related to performance characteristics for the database on the source system. On the basis of the collected source parameters and target parameters of the target system database configuration information is generated. The target parameters will affect the operation of the database on the target system as compared to the operation of the database on the source system. The database configuration information is applicable to tune the database to operate on the target system. The method further comprises configuring the database to run on the target system according to the database configuration information.
摘要:
In a partitioned database system that includes multiple logical partitions, query performance is estimated with a current allocation of resources. A determination is made whether additional resources are available or whether resources could be reallocated from one logical partition to a different logical partition. Query performance is then estimated again with a proposed reallocation of resources. This process continues iteratively until an allocation of resources is determined that will enhance the performance of the query. A resource allocation mechanism then initiates the reallocation of resources. In this manner, resources in logical partitions may be dynamically and autonomically reallocated to improve the performance of a query to a partitioned database.
摘要:
A database optimizer collects statistics regarding applications accessing a database, and makes one or more changes to the database schema to optimize performance according to the collected statistics. In a first embodiment, the optimizer detects when a certain type of application accesses the database a percentage of time that exceeds a predefined threshold level, and if the data in the database is stored in a less-than-optimal format for the application, the data type of one or more columns in the database is changed to a more optimal format for the application. In a second embodiment, the optimizer detects when one type of application accesses a column a percentage of time that exceeds a first predefined threshold level and is less than a second predefined threshold level, and creates a new column in the database so the data is present in both formats.
摘要:
Methods, articles of manufacture and systems for managing Web services. One embodiment provides a method comprising providing one or more rules configured to determine whether a Web service is deterministic. A deterministic Web service produces in subsequent executions identical output in response to identical input. The one or more rules are associated with the Web service.
摘要:
An apparatus, program product and method utilize one or more usage statistics, which are reflective of what data is actually and/or likely to be used by a client when processing a database query, to reduce or eliminate the transfer of unnecessary data between a client and server in a client-server database management system. Information such as the columns that are or have been used and/or the number of rows that have been accessed, may be utilized to identify certain data that is likely to not be used during processing of the database query. Based upon the data that has been identified, a subset of the data that would otherwise be returned as a result of the database query may be identified and returned to a client, often substantially reducing the amount of data required to be retrieved by a client in connection with a database query.