Abstract: Methods and systems are provided for executing a simulation of an operation in a data processing system. In one implementation, the method includes executing an operation under a first set of conditions, determining a characteristic associated with the execution of the operation under the first set of conditions, and executing a simulation of the operation under a second set of conditions different from the first set of conditions. The simulation of the operation is constrained by the determined characteristic. The method can further include determining a cost/benefit of executing the operation under a set of conditions different from the first set of conditions based at least in part on the simulation.

Abstract: There are disclosed systems, computer program products, and methods for self-tuning memory. In an embodiment, a method for self-tuning memory comprises setting a tuning interval and a target range for free memory for a memory pool. If memory consumption falls outside of the set target range for free memory during a tuning interval, a new target size for the memory pool is set based on the target range for free memory. Memory allocation for the memory pool is increased or decreased for the next tuning interval, such that the new target size for the memory pool is reached. A decrement rate may be used to provide a controlled decrease of the memory pool over a plurality of tuning intervals if necessary, until the new target size for the memory pool is reached.

Abstract: Providing cost model data for tuning query cache memory size in database systems. In one aspect, a query is received, and a query cache is checked for a stored query matching the received query. In response to a cache miss occurring, a token representing the received query is generated and checked for matching a token stored in a simulation area, each stored token representing a query object previously evicted from the query cache. A processing time saved by an avoidance of the cache miss is determined, and a cache size needed to avoid the cache miss is determined only when the generated token matches a stored token, by summing sizes of all query objects represented by the stored tokens. Each stored token is included in a stub that also includes the size of the represented query object and an identification number indicating a stored order.

Abstract: A method for reducing oscillations of an output value associated with a program to be operatively coupled to a data processing system. The program having an internal process configured to read an input value provided by the program, the input value adjusting a performance aspect of the internal process, the internal process configured to provide an output value reflecting changes in the internal process responsive to the input value, the output value readable by the program.