Added LeftOuterUnnestMap operator.

 - Added LeftOuterUnnestMap operator to represent the left-outer-join semantics properly.

Change-Id: I6760319c2d3ff90c8b7d8ddeea3d9dd8f743366b
Reviewed-on: https://asterix-gerrit.ics.uci.edu/637
Reviewed-by: Yingyi Bu <buyingyi@gmail.com>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
diff --git a/asterix-app/src/test/resources/optimizerts/results/multi-indexes/two-inverted-index-intersect.plan b/asterix-app/src/test/resources/optimizerts/results/multi-indexes/two-inverted-index-intersect.plan
index 7d99635..6b762e7 100644
--- a/asterix-app/src/test/resources/optimizerts/results/multi-indexes/two-inverted-index-intersect.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/multi-indexes/two-inverted-index-intersect.plan
@@ -9,18 +9,14 @@
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   -- STABLE_SORT [$$18(ASC)]  |PARTITIONED|
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                      -- STREAM_PROJECT  |PARTITIONED|
+                      -- LENGTH_PARTITIONED_INVERTED_INDEX_SEARCH  |PARTITIONED|
                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                          -- LENGTH_PARTITIONED_INVERTED_INDEX_SEARCH  |PARTITIONED|
-                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                              -- ASSIGN  |PARTITIONED|
-                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                          -- ASSIGN  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   -- STABLE_SORT [$$20(ASC)]  |PARTITIONED|
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                      -- STREAM_PROJECT  |PARTITIONED|
+                      -- LENGTH_PARTITIONED_INVERTED_INDEX_SEARCH  |PARTITIONED|
                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                          -- LENGTH_PARTITIONED_INVERTED_INDEX_SEARCH  |PARTITIONED|
-                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                              -- ASSIGN  |PARTITIONED|
-                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                          -- ASSIGN  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|