1. A method for multi-query optimization, the method comprising: identifying an input query set comprising a plurality of input queries over a given data set, each query comprising a graph pattern comprising at least one subject node, predicate edge and object node triple; and clustering the plurality of input queries though incremental pair-wise merging based on structural similarities between graph patterns and query search cost optimization realized by a given merged graph pattern to generate an optimized query set comprising at least one query cluster.