1. A method for storing data, comprising: representing the data as a tree structure; calculating a structure ID of the tree structure, the structure ID being a representation of the tree structure and independent of node names and node values of the tree structure, comprising: creating a main list comprising, for each node of the tree structure beginning from a highest level to a lowest level and from a left to right within each level, one of an element name, an attribute name, and an attribute value; assigning, as a node ID for each parent node of the tree structure, a position of the respective parent node within the main list; creating a parent-child table from the main list comprising each obtained node ID of each parent node of the tree structure and a number of child nodes of the respective parent node; assigning, to each parent node, a prime number at an index within an indexed set of prime numbers from a natural number set of numbers represented by the assigned node ID of the respective parent node; and calculating the structure ID from the parent-child table as a product of each resulting assigned prime number raised to a power of the number of child nodes of the respective parent node; and storing a mapping of the structure ID to the tree structure.