hpcc-systems/HPCC-Platform — pull request #698 by ghalliday (2011-10-17 11:15:48+00:00)
Title: Optimize DEDUP(ds, LEFT.x = RIGHT.x) in thor

It is now treated the same way as DEDUP(ds, x) - which generates a
group followed by a dedup, which tends to be much more efficient in
thor.

Signed-off-by: Gavin Halliday