摘要:
A method, apparatus, and computer program product are disclosed for managing query execution plans for a workload. In one embodiment, the method includes gathering an initial set of performance characteristics generated from a database management system (DBMS) executing a database workload according to one or more query execution plans (QEPs). The database workload includes one or more database statements. The method determines a QEP change for one or more QEPs of the database workload. In addition, the method gathers a subsequent set of performance characteristics generated from the DBMS executing the one or more QEPs of the database workload influenced by the QEP change. Furthermore, the method determines a performance difference created by the QEP change based on the initial set of performance characteristics and the subsequent set of performance characteristics and responds to the performance difference in accordance with a monitoring policy.
摘要:
A method, apparatus, and article of manufacture for a computer-implemented apportioning system. Work is distributed to processors in a multi-processor system. Initially, during bind-time, a scaling factor is determined for each processor. The scaling factor represents relative processing power in relation to each other processor. Then, portions of a total amount of work are distributed to each processor based on the determined scaling factor of that processor and a determined amount of work for an average processor.
摘要:
A method, apparatus, and article of manufacture for a computer implemented rebalancing system. Partitioned data is rebalanced in a database stored on a data storage device connected to a computer. Range values are redefined for each partition. Next, the data is reordered into the redefined ranges for the partitions.
摘要:
A multiprocessing system forms a data structure, such as by loading reorganizing, or recovering, while concurrently collecting various statistics about the data structure. The data structure may comprise tables and/or indices, for example. A first processing unit forms the data structure by assimilating data from one or more data sources into data rows, storing the rows in a buffer, and copying the rows from the buffer to the data structure. Concurrently with the forming step, the same or a second processing unit retrieves the rows from the buffer and applies a predetermined analysis to the rows to formulate statistics regarding the data structure.
摘要:
A method, apparatus, and article of manufacture for a computer implemented recover/build index system. The recover/build index system builds a database index for a database file by scanning partitions of the database file in parallel to retrieve key values and their associated record identifier (rid) values. The recover/build index system then sorts the scanned key/rid values for each partition in parallel. Next, the recover/build index system performs one or more merges on the sorted key/rid values from all of the partitions to generate a single key/rid value stream. Finally, the recover/build index system builds the index using the single key/rid value stream.