A method of storing multi-dimensional data, the method comprises encoding a structure of nodes of a tree data structure into an order representation; compressing data of nodes of the tree data structure to create a data stream of compressed data portions of variable length in a sequence corresponding to the order represented in the order representation. Each compressed data portion is formed from the data of each node. The method further comprises mapping the positions of the data portions in the data stream to the order representation to produce a location representation; and storing the order representation, data stream and location representation. A system of storing multi-dimensional data is also disclosed, as well as a method and system for retrieving stored multi-dimensional data.