1. A method for generating an index for searching data containers in a storage system, comprising a processor and a memory, based on selected metadata attributes, the method comprising: mapping, for a given data container of a plurality of data containers, a pair of values corresponding to a pair of attributes associated with metadata describing the given data container that stores data, wherein the pair of values represent coordinates for the given data container in a two-dimensional (2D) space; imposing a grid comprising a plurality of cells on the 2D space so that each cell in the grid represents coordinates of a single data container of the plurality of data containers in the 2D space; computing a space filling curve value for each cell in the grid; generating a searching index wherein each computed space filling curve value is used as a key in the searching index to search for the plurality of data containers in the storage system; receiving a query to search for one or more particular data containers based on ranges of metadata values of selected attributes; computing particular space-filling curve values based on the ranges of metadata values of selected attributes associated with the query; and searching the searching index to identify the one or more particular data containers based on the particular space-filling curve values.