Abstract: Relational data for a database table having multiple columns (dimensions) is represented as a histogram. The buckets of the histogram are clustered into clusters, the clusters are fewer in number than the buckets of the histogram. Each cluster is represented in hyper-space as a line segment (vector) with a thickness value. Average frequencies for the line segments (vectors) and their thickness values are computed. The average frequencies are processed by a query optimizer when processing a query predicate of a query to use as an estimation of selectivity or an estimation of a cardinality of a join operation.

Abstract: A system and method providing interrupted write protection to a stand-alone commodity storage array utilized within a database system. The method identifies writes of data from the database system to the storage array requiring interrupt protection, and for each write, generates an entry for an intent log maintained within the database system. The log entries include a write identifier, storage device information associated with a write, and a write statues indication which are used to identify failed writes following a database system failure.

Abstract: Methods, computer programs, and database systems for performing a database query to join two or more tables on a condition are disclosed. Each table includes one or more join columns. Each of the join columns includes zero or more join-column values. The method includes excluding join-column values that do not satisfy the condition, using one or more value-count indexes and performing the database query on non-excluded join-column values.

Abstract: A Value Analyzer system is a data-driven computer-facilitated financial model that provides accurate and consistent profitability calculations using account, product and event attributes stored in a relational database managed by a relational database management system (RDBMS). Profitability calculations are performed in the computer by applying one or more rules to the account, product and event attributes accessed from the database, wherein each of the rules is represented as one or more objects in a hierarchy, the objects include one or more relations, criteria lists and criteria, each of the relations includes one or more of the criteria lists, and each of the criteria lists includes one or more of the criteria, and the criteria determine which accounts, products and events are processed in the profitability calculations.