Patent ID: 8768953
Filing Date: 2014-07-01
Classification: G06F

Abstract:
1. A method for determining a rule predicate to be materialized, comprising: obtaining a dependency graph comprising a plurality of nodes, wherein each node corresponds to one or more rule predicates, and the nodes of the dependency graph are not strongly connected to one another, wherein the dependency graph indicates dependencies among the plurality of nodes; calculating an update frequency of the plurality of nodes in the dependency graph; calculating a query frequency of the plurality of nodes in the dependency graph; calculating a runtime query cost value and a materialization cost value of the plurality of nodes based on the query frequency and the update frequency; and determining at least one node of the plurality of nodes to be materialized based on the runtime query cost value and the materialization cost value, wherein at least one of the rule predicates, corresponding to the at least one node to be materialized, comprises the rule predicate to be materialized; wherein calculating the runtime query cost value and the materialization cost value based on the query frequency and the update frequency further comprises: setting a single reassessment cost value Ce of the node; setting a single query cost value Cq of the node; calculating the materialization cost value Em of the node by using formula Em=Ce+n.UF*Ce, wherein n.UF represents the update frequency of the node; and calculating the runtime query cost value of the node Eq by using formula Eq=n.QF*Cq, wherein n.QF represents the query frequency of the node.