1. A large-scale data processing system, comprising: an interface, being configured to access a multi-dimensional data model stored in a storage device, wherein the multi-dimensional data model comprises a plurality of dimensions, the dimensions form a multi-dimensional space of measures, each dimension is a single space comprising a plurality of members with a common set of attributes, and each measure is a data element organized and accessible through the multi-dimensional space of the cross-product of all dimensions; and a processor, being electrically connected to the interface and configured to access the multi-dimensional data model via the interface and build at least one Tree Object (TO), wherein the TO is derived by converting the multi-dimensional data model into an N-level tree data structure according to a level order of N attributes, each tree node in the TO meets all conditions of attributes for all ancestor nodes, and N is a positive integer wherein the processor further performs a Select operation for locating at least one subtree of the TO, the at least one located subtree meets a path condition described by XPath, and the path condition represents a sequence of attributes corresponding to the level order of the TO.