Patent ID: 7571188
Filing Date: 2009-08-04
Classification: G06F,Y10S

Abstract:
1. A method for modeling a database management system using a cache hierarchy, comprising: receiving a query to be searched in the cache hierarchy, wherein the cache hierarchy comprises a first cache and a second cache, computing a hit rate value associated with the first cache in the cache hierarchy, wherein the hit rate value is computed based, in part, on a counter group, wherein computing the hit rate value comprises computing a ratio of current contents of the first cache over a size of a file associated with the query, and wherein the file is cached in the first cache; comparing the hit rate value to a predetermined value to obtain a result, wherein the predetermined value is a number randomly selected from a uniform distribution, wherein a hit is determined when the predetermined value is not greater than the hit rate value; providing a reply to the query when the result corresponds to the hit; incrementing a counter in the counter group when the first cache is not full; proceeding to the second cache in the cache hierarchy when the result is a miss; and providing a diagnostic output comprising a overall performance for the database management system, wherein the overall performance is determined, in part, on the delay caused by the locking mechanism associated with the first partition.