Method and system for facilitating processing of statistical inquires on

Abstract

A data access structure facilitates the processing of statistical queries concerning records stored in the structure. The structure, according to the present invention, includes a plurality of data nodes storing the records, and a plurality of access nodes, each storing at least one pointer to another access node or to a data node, and arranged according to an organization whereby each access node is linked directly or indirectly to at least one data node. Statistical information is stored in or linked to the nodes of a subset of the plurality of access nodes and data nodes. The statistical information concerns the records stored in the data node or data nodes linked directly or indirectly to the respective nodes of the subset. Further, a software algorithm is provided responsive to changes in the records stored in the data nodes for updating the statistical information in the access structure concerning the records stored in the data node. The present invention is suitable for implementation with a wide variety of hierarchical and non-hierarchical access methods, including those based on the B-tree, ISAM, RRDS (Relative Record Data Set) of IBM VSAM, and HDAM of IBM IMS.