Data extraction and sparseness discovery from multidimensional databases

摘要

Techniques for a method for efficiently extracting data from multidimensional databases are disclosed herein. When extracting data from a subset of a multidimensional database, the method first extracts data from high-level cells within the subset. If there are any empty high-level cells, the method removes lower-level cells that roll-up into the empty high-level cell, without extracting data from these lower-level cells. The method improves the data extraction efficiency by reducing the overhead of extracting data from empty cells of multidimensional databases.

主权项

1. A method comprising:
receiving a request to extract data from a subset of a multidimensional database that stores data at a plurality of cells, wherein the subset has a plurality of dimension members, and each dimension member of the plurality of dimension members belongs to a dimension of a plurality of dimensions of the multidimensional database; determining, from the subset, a reduced subset by excluding a plurality of empty cells from the subset, wherein determining the reduced subset comprises:
identifying all top-level members from a plurality of dimension members that define the subset, wherein values of the top-level members do not roll up into a value of any ancestor member from the plurality of dimension members;extracting at least one data value from at least one high-level cell located by at least one of the top-level members and a group of dimension members from the plurality of dimension members; andresponsive to determining that the at least one data value is an empty data value, determining, from the subset, a reduced subset by excluding roll-up cells of the at least one high-level cell from the reduced subset, wherein each of the roll-up cells is located by a descendent member of the at least one of the top-level members and the group of dimension members; and satisfying the request by extracting data values from only the reduced subset and without extracting data values from the excluded roll-up cells.