A capability is provided for representing a set of data values using data structures, including converting a binary trie data structure representing the set of data values to a shape graph data structure representing the set of data values. The shape graph data structure is generated from the binary trie data structure based on the shapes of the sub-trees rooted at the nodes of the binary trie data structure. The shape graph includes vertices representing shapes of the sub-trees of the binary trie data structure. A shape graph data structure permits operations similar to the operations that may be performed on the binary trie data structure for performing lookups for data values from the set of data values, while at the same time reducing the structural redundancy of the binary trie data structure such that the shape graph data structure provides significant improvements in memory usage over the binary trie data structure.