Fixed ASTERIXDB-1249 and ASTERIXDB-1250: self index-nested-loop join correctly identifies the outer and the inner branch.

The first dataset becomes the outer branch.
The second dataset becomes the inner branch.
The optimizer for index-nested-loop join now only try to use an index from the inner branch.

Change-Id: I0d4291197c2bcfbcdcde998c5952af41960c4ad7
Reviewed-on: https://asterix-gerrit.ics.uci.edu/576
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/btree-index-join/secondary-self-equi-join.plan b/asterix-app/src/test/resources/optimizerts/results/btree-index-join/secondary-self-equi-join.plan
new file mode 100644
index 0000000..1d99ed8
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/results/btree-index-join/secondary-self-equi-join.plan
@@ -0,0 +1,26 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- STREAM_PROJECT  |PARTITIONED|
+      -- ASSIGN  |PARTITIONED|
+        -- SORT_MERGE_EXCHANGE [$$15(ASC) ]  |PARTITIONED|
+          -- STREAM_PROJECT  |PARTITIONED|
+            -- STREAM_SELECT  |PARTITIONED|
+              -- STREAM_PROJECT  |PARTITIONED|
+                -- ASSIGN  |PARTITIONED|
+                  -- STREAM_PROJECT  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- BTREE_SEARCH  |PARTITIONED|
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          -- STABLE_SORT [$$21(ASC)]  |PARTITIONED|
+                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                              -- STREAM_PROJECT  |PARTITIONED|
+                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                  -- BTREE_SEARCH  |PARTITIONED|
+                                    -- BROADCAST_EXCHANGE  |PARTITIONED|
+                                      -- STREAM_PROJECT  |PARTITIONED|
+                                        -- ASSIGN  |PARTITIONED|
+                                          -- STREAM_PROJECT  |PARTITIONED|
+                                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                              -- DATASOURCE_SCAN  |PARTITIONED|
+                                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|