Mining for Empty Rectangles in Large Data Sets Jeff Edmonds, Jarek Gryz, Dongming Liang, Renee J. Miller Many data mining approaches focus on the discovery of similar (and frequent) data values in large data sets. We present an alternative, but complementary approach in which we search for empty regions in the data. We consider the problem of finding maximal empty rectangles in large, two dimensional data sets. We introduce a novel, scalable algorithm for finding all such rectangles. The algorithm achieves this with a single scan over a sorted data set and requires only a small bounded amount of memory. We also describe briefly one potential application of this knowledge to query optimization.