apache/spark — pull request #1004 by marmbrus (2014-06-07 01:41:35+00:00)
Title: [SPARK-1994][SQL] Weird data corruption bug when running Spark SQL on data in HDFS

Basically there is a race condition (possibly a scala bug?) when these values are recomputed on all of the slaves that results in an incorrect projection being generated (possibly because the GUID uniqueness contract is broken?).

In general we should probably enforce that all expression planing occurs on the driver, as is now occurring here.