Patent ID: 7921085
Filing Date: 2011-04-05
Classification: G06F

Abstract:
1. A method for quantifying a data page repetition pattern for a database index in a database management system, the method comprising: identifying a database index to provide a basis for collecting a data page repetition statistic for the database index, the database index having a database index key, the database index stored on a computer readable storage medium, wherein the data page repetition statistic quantifies a data page repetition pattern associated with database queries that reference sequential entries of the database index, the data page repetition pattern comprising a pattern of out of order references to data storage pages by the sequential entries of the database index such that a data storage page is repeatedly cached into a cache memory during an operational database search; conducting a statistic collection scan of the database index to identify a data storage page identifier for a data entry corresponding to each database index key value in the database index, the identified database index ordered by database index key, the statistic collection scan collecting the data page repetition statistic by examining each entry in the identified database index in order; defining a logical window to represent successive sets of data storage pages during the statistic collection scan, the logical window beginning at a first data storage page associated with a first index key in the database index and having a size of one data storage page that stores a data entry corresponding to the first index key value, the logical window simulating a model of the successive sets of data storage pages referenced by the database index that may be cached into the cache memory; increasing the size of the logical window up to a maximum size in response to a determination that the statistic collection scan references a data storage page not included within the logical window; incrementing a counter in response to a determination that one of the size of the logical window and a position of the logical window is adjusted due to the statistic collection scan, the data page repetition statistic based on a value of the counter; and optimizing a data page access process for a database query that is received subsequent to the statistic collection scan, the optimization based on the data page repetition statistic.