ASTERIXDB-221: reduce unneceesary partitioning for hash joins.

Fixed broken optimizer tests

Change-Id: I0c8b4208c095d95e06357af6d2e9e465c74dec19
Reviewed-on: https://asterix-gerrit.ics.uci.edu/445
Reviewed-by: Ian Maxon <imaxon@apache.org>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
diff --git a/asterix-app/src/test/resources/optimizerts/results/loj-super-key_01.plan b/asterix-app/src/test/resources/optimizerts/results/loj-super-key_01.plan
index 60e9899..dfcda62 100644
--- a/asterix-app/src/test/resources/optimizerts/results/loj-super-key_01.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/loj-super-key_01.plan
@@ -16,13 +16,13 @@
                     -- STREAM_PROJECT  |PARTITIONED|
                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                         -- HYBRID_HASH_JOIN [$$24, $$22, $$28][$$25, $$19, $$20]  |PARTITIONED|
-                          -- HASH_PARTITION_EXCHANGE [$$24, $$22, $$28]  |PARTITIONED|
+                          -- HASH_PARTITION_EXCHANGE [$$22, $$28]  |PARTITIONED|
                             -- ASSIGN  |PARTITIONED|
                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                 -- DATASOURCE_SCAN  |PARTITIONED|
                                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                     -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
-                          -- HASH_PARTITION_EXCHANGE [$$25, $$19, $$20]  |PARTITIONED|
+                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             -- ASSIGN  |PARTITIONED|
                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                 -- DATASOURCE_SCAN  |PARTITIONED|