diff --git a/asterix-app/src/test/resources/optimizerts/queries/query_issue849-2.aql b/asterix-app/src/test/resources/optimizerts/queries/query_issue849-2.aql
new file mode 100644
index 0000000..929c5f1
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/queries/query_issue849-2.aql
@@ -0,0 +1,24 @@
+/*
+ * Description  : This test case is to verify the fix for issue827
+ * https://code.google.com/p/asterixdb/issues/detail?id=849
+ * Expected Res : SUCCESS
+ * Date         : 2nd Feb. 2015
+ */
+
+drop dataverse test if exists;
+create dataverse test;
+
+use dataverse test;
+
+create type sType as closed{b : int32};
+create dataset s(sType) primary key b;
+
+insert into dataset s ({ "b" : 1});
+insert into dataset s ({ "b" : 3});
+
+for $x in dataset s
+for $y in (
+ for $z in {{ {"a":1, "c":1},{"a":2, "c":2},{"a":1, "c":null} }} where $x.b=$z.a
+    return $z.c
+)
+return {"x":$x,"y":$y}
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/optimizerts/queries/query_issue849.aql b/asterix-app/src/test/resources/optimizerts/queries/query_issue849.aql
new file mode 100644
index 0000000..5e45938
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/queries/query_issue849.aql
@@ -0,0 +1,24 @@
+/*
+ * Description  : This test case is to verify the fix for issue827
+ * https://code.google.com/p/asterixdb/issues/detail?id=849
+ * Expected Res : SUCCESS
+ * Date         : 2nd Feb. 2015
+ */
+
+drop dataverse test if exists;
+create dataverse test;
+
+use dataverse test;
+
+create type sType as closed{b : int32};
+create dataset s(sType) primary key b;
+
+insert into dataset s ({ "b" : 1});
+insert into dataset s ({ "b" : 3});
+
+for $x in {{ {"a":1},{"a":2} }}
+for $y in (
+ for $z in dataset s where $x.a=$z.b
+    return $z.b
+)
+return {"x":$x,"y":$y}
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/optimizerts/results/query_issue849-2.plan b/asterix-app/src/test/resources/optimizerts/results/query_issue849-2.plan
new file mode 100644
index 0000000..df5d477
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/results/query_issue849-2.plan
@@ -0,0 +1,33 @@
+-- COMMIT  |PARTITIONED|
+  -- STREAM_PROJECT  |PARTITIONED|
+    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+      -- INSERT_DELETE  |PARTITIONED|
+        -- HASH_PARTITION_EXCHANGE [$$3]  |PARTITIONED|
+          -- ASSIGN  |UNPARTITIONED|
+            -- ASSIGN  |UNPARTITIONED|
+              -- EMPTY_TUPLE_SOURCE  |UNPARTITIONED|
+-- COMMIT  |PARTITIONED|
+  -- STREAM_PROJECT  |PARTITIONED|
+    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+      -- INSERT_DELETE  |PARTITIONED|
+        -- HASH_PARTITION_EXCHANGE [$$3]  |PARTITIONED|
+          -- ASSIGN  |UNPARTITIONED|
+            -- ASSIGN  |UNPARTITIONED|
+              -- EMPTY_TUPLE_SOURCE  |UNPARTITIONED|
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- STREAM_PROJECT  |PARTITIONED|
+      -- ASSIGN  |PARTITIONED|
+        -- STREAM_PROJECT  |PARTITIONED|
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+            -- HYBRID_HASH_JOIN [$$15][$$17]  |PARTITIONED|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                -- DATASOURCE_SCAN  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+              -- HASH_PARTITION_EXCHANGE [$$17]  |PARTITIONED|
+                -- STREAM_PROJECT  |UNPARTITIONED|
+                  -- ASSIGN  |UNPARTITIONED|
+                    -- STREAM_SELECT  |UNPARTITIONED|
+                      -- UNNEST  |UNPARTITIONED|
+                        -- EMPTY_TUPLE_SOURCE  |UNPARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/query_issue849.plan b/asterix-app/src/test/resources/optimizerts/results/query_issue849.plan
new file mode 100644
index 0000000..db12ea3
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/results/query_issue849.plan
@@ -0,0 +1,33 @@
+-- COMMIT  |PARTITIONED|
+  -- STREAM_PROJECT  |PARTITIONED|
+    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+      -- INSERT_DELETE  |PARTITIONED|
+        -- HASH_PARTITION_EXCHANGE [$$3]  |PARTITIONED|
+          -- ASSIGN  |UNPARTITIONED|
+            -- ASSIGN  |UNPARTITIONED|
+              -- EMPTY_TUPLE_SOURCE  |UNPARTITIONED|
+-- COMMIT  |PARTITIONED|
+  -- STREAM_PROJECT  |PARTITIONED|
+    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+      -- INSERT_DELETE  |PARTITIONED|
+        -- HASH_PARTITION_EXCHANGE [$$3]  |PARTITIONED|
+          -- ASSIGN  |UNPARTITIONED|
+            -- ASSIGN  |UNPARTITIONED|
+              -- EMPTY_TUPLE_SOURCE  |UNPARTITIONED|
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- STREAM_PROJECT  |PARTITIONED|
+      -- ASSIGN  |PARTITIONED|
+        -- STREAM_PROJECT  |PARTITIONED|
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+            -- HYBRID_HASH_JOIN [$$17][$$14]  |PARTITIONED|
+              -- HASH_PARTITION_EXCHANGE [$$17]  |PARTITIONED|
+                -- ASSIGN  |UNPARTITIONED|
+                  -- UNNEST  |UNPARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |UNPARTITIONED|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                -- STREAM_PROJECT  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- DATASOURCE_SCAN  |PARTITIONED|
+                      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                        -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
diff --git a/asterix-app/src/test/resources/optimizerts/results/rtree-index-join/query-issue838.plan b/asterix-app/src/test/resources/optimizerts/results/rtree-index-join/query-issue838.plan
index 34c71b9..56f292c 100644
--- a/asterix-app/src/test/resources/optimizerts/results/rtree-index-join/query-issue838.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/rtree-index-join/query-issue838.plan
@@ -2,25 +2,22 @@
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
       -- ASSIGN  |PARTITIONED|
-        -- SORT_MERGE_EXCHANGE [$$18(ASC) ]  |PARTITIONED|
-          -- STABLE_SORT [$$18(ASC)]  |PARTITIONED|
-            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-              -- STREAM_PROJECT  |PARTITIONED|
-                -- STREAM_SELECT  |PARTITIONED|
-                  -- STREAM_PROJECT  |PARTITIONED|
-                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                      -- BTREE_SEARCH  |PARTITIONED|
-                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                          -- STABLE_SORT [$$29(ASC)]  |PARTITIONED|
-                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                              -- STREAM_PROJECT  |PARTITIONED|
-                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                  -- RTREE_SEARCH  |PARTITIONED|
-                                    -- BROADCAST_EXCHANGE  |PARTITIONED|
-                                      -- ASSIGN  |PARTITIONED|
-                                        -- STREAM_PROJECT  |PARTITIONED|
-                                          -- ASSIGN  |PARTITIONED|
-                                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                              -- DATASOURCE_SCAN  |PARTITIONED|
-                                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
+        -- STREAM_PROJECT  |PARTITIONED|
+          -- STREAM_SELECT  |PARTITIONED|
+            -- STREAM_PROJECT  |PARTITIONED|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                -- BTREE_SEARCH  |PARTITIONED|
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    -- STABLE_SORT [$$29(ASC)]  |PARTITIONED|
+                      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                        -- STREAM_PROJECT  |PARTITIONED|
+                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                            -- RTREE_SEARCH  |PARTITIONED|
+                              -- BROADCAST_EXCHANGE  |PARTITIONED|
+                                -- ASSIGN  |PARTITIONED|
+                                  -- STREAM_PROJECT  |PARTITIONED|
+                                    -- ASSIGN  |PARTITIONED|
+                                      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                        -- DATASOURCE_SCAN  |PARTITIONED|
+                                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file