Abstract: A method, apparatus and program product use a first index associated with a field in a database table to identify a range of records in the database table that includes instances of a first key value in the field and use the identified range of records to subset a second index associated with another field in a database table. The database query identifies the first key value for the field in the database table and the second key value for the other field in the database table. By doing so, information from an index may be carried over and applied to another index to subset the other index, often reducing the quantity of entries that are searched in the other index and improving performance.

Abstract: A query facility for database queries saves and re-uses query execution strategies, and automatically detects that a strategy should be re-optimized as a result of changes to an indexed variable value. Preferably, the number of records evaluated and selected by the index value condition is dynamically monitored during execution, and an alternative query strategy is initiated when this number appears to be out of proportion to expectations. In an exemplary embodiment, an indexed search strategy is changed to a table scan strategy (or vice versa) as a result of a change to the number of records eliminated by the indexed value, although other examples are possible. Preferably, the query engine initiates an alternative search strategy and concurrently continues to execute the original search strategy as separate threads. Search results are obtained from whichever thread completes first.

Abstract: A method, apparatus, and program product utilize intelligent job functionality to diagnose an error in a computer. After detecting an error in a first job processing a task, and in response to another attempt to perform the task, a job selection algorithm selects a predetermined job in which to perform the task and diagnose the error. The predetermined job can be the first job or a new job associated with a signature that corresponds to the task that experienced the error. The predetermined job can be used to diagnose the error in a debugging session. Alternately, the first job may enter a debug session immediately after experiencing an error.

Abstract: The invention, in an embodiment, relates to optimizing database performance by taking advantage of sleepy drives. The invention analyzes queries to indexes based on usage frequency, and determines whether to access an index stored on a sleepy drive, or perform an alternate access plan based on green optimization. Furthermore, the invention transfers data, such as, for example, indexes, files, data areas, journals, and statistics, between active and sleepy drives based on usage frequency. In another embodiment, the invention provides an improved sleepy drive which optimizes energy savings by a graduated degree based on a speed setting. In yet another embodiment, the invention controls when read-write heads are unloaded from disks to reduce drag and power consumption by a disk drive.

Abstract: A method, apparatus and program product use a first index associated with a field in a database table to identify a range of records in the database table that includes instances of a first key value in the field and use the identified range of records to subset a second index associated with another field in a database table. The database query identifies the first key value for the field in the database table and the second key value for the other field in the database table. By doing so, information from an index may be carried over and applied to another index to subset the other index, often reducing the quantity of entries that are searched in the other index and improving performance.

Abstract: A method, apparatus, and program product utilize intelligent job functionality to diagnose an error in a computer. After detecting an error in a first job processing a task, and in response to another attempt to perform the task, a job selection algorithm selects a predetermined job in which to perform the task and diagnose the error. The predetermined job can be the first job or a new job associated with a signature that corresponds to the task that experienced the error. The predetermined job can be used to diagnose the error in a debugging session. Alternately, the first job may enter a debug session immediately after experiencing an error.