apache/spark — pull request #2561 by saucam (2014-09-28 06:01:10+00:00)
Title: SPARK-3711: Optimize where in clause filter queries

The In case class is replaced by a InSet class in case all the filters are literals, which uses a hashset instead of Sequence, thereby giving significant performance improvement (earlier the seq was using a worst case linear match (exists method) since expressions were assumed in the filter list) . Maximum improvement should be visible in case small percentage of large data matches the filter list.