diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.1.ddl.sqlpp
new file mode 100644
index 0000000..2a616ea
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.1.ddl.sqlpp
@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+DROP DATAVERSE TinySocial IF EXISTS;
+CREATE DATAVERSE TinySocial;
+
+USE TinySocial;
+
+CREATE TYPE EmploymentType AS CLOSED
+{
+  `organization-name` : string,
+  `start-date` : date,
+  `end-date` : date?
+};
+
+CREATE TYPE FacebookUserType AS CLOSED {
+  id : bigint,
+  alias : string,
+  name : string,
+  `user-since` : datetime,
+  `friend-ids` : {{bigint}},
+  employment : [EmploymentType]
+};
+
+CREATE TYPE FacebookMessageType AS CLOSED {
+  `message-id` : bigint,
+  `author-id` : bigint,
+  `in-response-to` : bigint?,
+  `sender-location` : point?,
+  message : string
+};
+
+CREATE DATASET FacebookUsers(FacebookUserType) PRIMARY KEY id;
+
+CREATE DATASET FacebookMessages(FacebookMessageType) PRIMARY KEY `message-id`;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.2.update.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.2.update.sqlpp
new file mode 100644
index 0000000..3d785ad
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.2.update.sqlpp
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+USE TinySocial;
+
+LOAD DATASET FacebookUsers using localfs (("path"="asterix_nc1://data/tinysocial/fbu.adm"),("format"="adm"));
+
+LOAD DATASET FacebookMessages using localfs (("path"="asterix_nc1://data/tinysocial/fbm.adm"),("format"="adm"));
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.3.query.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.3.query.sqlpp
new file mode 100644
index 0000000..003ec26
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.3.query.sqlpp
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+USE TinySocial;
+-- Disabled for a simpler plan
+SET `compiler.sort.parallel` "false";
+
+
+    SELECT "message1" ds, s.`message-id` id, object_remove(s, "in-response-to") no_in_response_to
+    FROM FacebookMessages AS s
+UNION ALL
+    SELECT "user" ds, t.id id, t user
+    FROM FacebookUsers t
+UNION ALL
+    SELECT "message2" ds, s.`message-id` id, object_remove(s, "author-id") no_author_id
+    FROM FacebookMessages s
+ORDER BY id, ds;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.4.query.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.4.query.sqlpp
new file mode 100644
index 0000000..cc63b57
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/union/union_type_cast/union_type_cast.4.query.sqlpp
@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+USE TinySocial;
+-- Disabled for a simpler plan
+SET `compiler.sort.parallel` "false";
+
+-- To prevent the plan from changing
+SET `compiler.parallelism` "0";
+
+EXPLAIN
+    SELECT s.`message-id` id, object_remove(s, "in-response-to") no_in_response_to
+    FROM FacebookMessages AS s
+UNION ALL
+    SELECT t.id id, t user
+    FROM FacebookUsers t
+UNION ALL
+    SELECT s.`message-id` id, object_remove(s, "author-id") no_author_id
+    FROM FacebookMessages s
+ORDER BY id;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/results/union/union_type_cast/union_type_cast.3.adm b/asterixdb/asterix-app/src/test/resources/runtimets/results/union/union_type_cast/union_type_cast.3.adm
new file mode 100644
index 0000000..cefb946
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/results/union/union_type_cast/union_type_cast.3.adm
@@ -0,0 +1,40 @@
+{ "ds": "message1", "id": 1, "no_in_response_to": { "message-id": 1, "author-id": 3, "sender-location": point("47.16,77.75"), "message": " love sprint its shortcut-menu is awesome:)" } }
+{ "ds": "message2", "id": 1, "no_author_id": { "message-id": 1, "in-response-to": 2, "sender-location": point("47.16,77.75"), "message": " love sprint its shortcut-menu is awesome:)" } }
+{ "ds": "user", "id": 1, "user": { "id": 1, "alias": "Margarita", "name": "MargaritaStoddard", "user-since": datetime("2012-08-20T10:10:00.000"), "friend-ids": {{ 2, 3, 6, 10 }}, "employment": [ { "organization-name": "Codetechno", "start-date": date("2006-08-06") } ] } }
+{ "ds": "message1", "id": 2, "no_in_response_to": { "message-id": 2, "author-id": 1, "sender-location": point("41.66,80.87"), "message": " dislike iphone its touch-screen is horrible" } }
+{ "ds": "message2", "id": 2, "no_author_id": { "message-id": 2, "in-response-to": 4, "sender-location": point("41.66,80.87"), "message": " dislike iphone its touch-screen is horrible" } }
+{ "ds": "user", "id": 2, "user": { "id": 2, "alias": "Isbel", "name": "IsbelDull", "user-since": datetime("2011-01-22T10:10:00.000"), "friend-ids": {{ 1, 4 }}, "employment": [ { "organization-name": "Hexviafind", "start-date": date("2010-04-27") } ] } }
+{ "ds": "message1", "id": 3, "no_in_response_to": { "message-id": 3, "author-id": 2, "sender-location": point("48.09,81.01"), "message": " like samsung the plan is amazing" } }
+{ "ds": "message2", "id": 3, "no_author_id": { "message-id": 3, "in-response-to": 4, "sender-location": point("48.09,81.01"), "message": " like samsung the plan is amazing" } }
+{ "ds": "user", "id": 3, "user": { "id": 3, "alias": "Emory", "name": "EmoryUnk", "user-since": datetime("2012-07-10T10:10:00.000"), "friend-ids": {{ 1, 5, 8, 9 }}, "employment": [ { "organization-name": "geomedia", "start-date": date("2010-06-17"), "end-date": date("2010-01-26") } ] } }
+{ "ds": "message1", "id": 4, "no_in_response_to": { "message-id": 4, "author-id": 1, "sender-location": point("37.73,97.04"), "message": " can't stand at&t the network is horrible:(" } }
+{ "ds": "message2", "id": 4, "no_author_id": { "message-id": 4, "in-response-to": 2, "sender-location": point("37.73,97.04"), "message": " can't stand at&t the network is horrible:(" } }
+{ "ds": "user", "id": 4, "user": { "id": 4, "alias": "Nicholas", "name": "NicholasStroh", "user-since": datetime("2010-12-27T10:10:00.000"), "friend-ids": {{ 2 }}, "employment": [ { "organization-name": "Zamcorporation", "start-date": date("2010-06-08") } ] } }
+{ "ds": "message1", "id": 5, "no_in_response_to": { "message-id": 5, "author-id": 6, "sender-location": point("34.7,90.76"), "message": " love sprint the customization is mind-blowing" } }
+{ "ds": "message2", "id": 5, "no_author_id": { "message-id": 5, "in-response-to": 2, "sender-location": point("34.7,90.76"), "message": " love sprint the customization is mind-blowing" } }
+{ "ds": "user", "id": 5, "user": { "id": 5, "alias": "Von", "name": "VonKemble", "user-since": datetime("2010-01-05T10:10:00.000"), "friend-ids": {{ 3, 6, 10 }}, "employment": [ { "organization-name": "Kongreen", "start-date": date("2010-11-27") } ] } }
+{ "ds": "message1", "id": 6, "no_in_response_to": { "message-id": 6, "author-id": 2, "sender-location": point("31.5,75.56"), "message": " like t-mobile its platform is mind-blowing" } }
+{ "ds": "message2", "id": 6, "no_author_id": { "message-id": 6, "in-response-to": 1, "sender-location": point("31.5,75.56"), "message": " like t-mobile its platform is mind-blowing" } }
+{ "ds": "user", "id": 6, "user": { "id": 6, "alias": "Willis", "name": "WillisWynne", "user-since": datetime("2005-01-17T10:10:00.000"), "friend-ids": {{ 1, 3, 7 }}, "employment": [ { "organization-name": "jaydax", "start-date": date("2009-05-15") } ] } }
+{ "ds": "message1", "id": 7, "no_in_response_to": { "message-id": 7, "author-id": 5, "sender-location": point("32.91,85.05"), "message": " dislike sprint the speed is horrible" } }
+{ "ds": "message2", "id": 7, "no_author_id": { "message-id": 7, "in-response-to": 15, "sender-location": point("32.91,85.05"), "message": " dislike sprint the speed is horrible" } }
+{ "ds": "user", "id": 7, "user": { "id": 7, "alias": "Suzanna", "name": "SuzannaTillson", "user-since": datetime("2012-08-07T10:10:00.000"), "friend-ids": {{ 6 }}, "employment": [ { "organization-name": "Labzatron", "start-date": date("2011-04-19") } ] } }
+{ "ds": "message1", "id": 8, "no_in_response_to": { "message-id": 8, "author-id": 1, "sender-location": point("40.33,80.87"), "message": " like verizon the 3G is awesome:)" } }
+{ "ds": "message2", "id": 8, "no_author_id": { "message-id": 8, "in-response-to": 11, "sender-location": point("40.33,80.87"), "message": " like verizon the 3G is awesome:)" } }
+{ "ds": "user", "id": 8, "user": { "id": 8, "alias": "Nila", "name": "NilaMilliron", "user-since": datetime("2008-01-01T10:10:00.000"), "friend-ids": {{ 3 }}, "employment": [ { "organization-name": "Plexlane", "start-date": date("2010-02-28") } ] } }
+{ "ds": "message1", "id": 9, "no_in_response_to": { "message-id": 9, "author-id": 3, "sender-location": point("34.45,96.48"), "message": " love verizon its wireless is good" } }
+{ "ds": "message2", "id": 9, "no_author_id": { "message-id": 9, "in-response-to": 12, "sender-location": point("34.45,96.48"), "message": " love verizon its wireless is good" } }
+{ "ds": "user", "id": 9, "user": { "id": 9, "alias": "Woodrow", "name": "WoodrowNehling", "user-since": datetime("2005-09-20T10:10:00.000"), "friend-ids": {{ 3, 10 }}, "employment": [ { "organization-name": "Zuncan", "start-date": date("2003-04-22"), "end-date": date("2009-12-13") } ] } }
+{ "ds": "message1", "id": 10, "no_in_response_to": { "message-id": 10, "author-id": 1, "sender-location": point("42.5,70.01"), "message": " can't stand motorola the touch-screen is terrible" } }
+{ "ds": "message2", "id": 10, "no_author_id": { "message-id": 10, "in-response-to": 12, "sender-location": point("42.5,70.01"), "message": " can't stand motorola the touch-screen is terrible" } }
+{ "ds": "user", "id": 10, "user": { "id": 10, "alias": "Bram", "name": "BramHatch", "user-since": datetime("2010-10-16T10:10:00.000"), "friend-ids": {{ 1, 5, 9 }}, "employment": [ { "organization-name": "physcane", "start-date": date("2007-06-05"), "end-date": date("2011-11-05") } ] } }
+{ "ds": "message1", "id": 11, "no_in_response_to": { "message-id": 11, "author-id": 1, "sender-location": point("38.97,77.49"), "message": " can't stand at&t its plan is terrible" } }
+{ "ds": "message2", "id": 11, "no_author_id": { "message-id": 11, "in-response-to": 1, "sender-location": point("38.97,77.49"), "message": " can't stand at&t its plan is terrible" } }
+{ "ds": "message1", "id": 12, "no_in_response_to": { "message-id": 12, "author-id": 10, "sender-location": point("42.26,77.76"), "message": " can't stand t-mobile its voicemail-service is OMG:(" } }
+{ "ds": "message2", "id": 12, "no_author_id": { "message-id": 12, "in-response-to": 6, "sender-location": point("42.26,77.76"), "message": " can't stand t-mobile its voicemail-service is OMG:(" } }
+{ "ds": "message1", "id": 13, "no_in_response_to": { "message-id": 13, "author-id": 10, "sender-location": point("42.77,78.92"), "message": " dislike iphone the voice-command is bad:(" } }
+{ "ds": "message2", "id": 13, "no_author_id": { "message-id": 13, "in-response-to": 4, "sender-location": point("42.77,78.92"), "message": " dislike iphone the voice-command is bad:(" } }
+{ "ds": "message1", "id": 14, "no_in_response_to": { "message-id": 14, "author-id": 9, "sender-location": point("41.33,85.28"), "message": " love at&t its 3G is good:)" } }
+{ "ds": "message2", "id": 14, "no_author_id": { "message-id": 14, "in-response-to": 12, "sender-location": point("41.33,85.28"), "message": " love at&t its 3G is good:)" } }
+{ "ds": "message1", "id": 15, "no_in_response_to": { "message-id": 15, "author-id": 7, "sender-location": point("44.47,67.11"), "message": " like iphone the voicemail-service is awesome" } }
+{ "ds": "message2", "id": 15, "no_author_id": { "message-id": 15, "in-response-to": 11, "sender-location": point("44.47,67.11"), "message": " like iphone the voicemail-service is awesome" } }
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/results/union/union_type_cast/union_type_cast.4.adm b/asterixdb/asterix-app/src/test/resources/runtimets/results/union/union_type_cast/union_type_cast.4.adm
new file mode 100644
index 0000000..b8d5203
--- /dev/null
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/results/union/union_type_cast/union_type_cast.4.adm
@@ -0,0 +1,72 @@
+distribute result [$#1]
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  exchange
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    project ([$#1])
+    -- STREAM_PROJECT  |PARTITIONED|
+      exchange
+      -- SORT_MERGE_EXCHANGE [$$102(ASC) ]  |PARTITIONED|
+        order (ASC, $$102)
+        -- STABLE_SORT [$$102(ASC)]  |PARTITIONED|
+          exchange
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+            union ($$64, $$140, $#1) ($$103, $$70, $$102)
+            -- UNION_ALL  |PARTITIONED|
+              exchange
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                union ($$139, $$141, $$64) ($$68, $$69, $$103)
+                -- UNION_ALL  |PARTITIONED|
+                  exchange
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    project ([$$139, $$68])
+                    -- STREAM_PROJECT  |PARTITIONED|
+                      assign [$$139] <- [cast({"id": $$68, "no_in_response_to": object-remove($$s, "in-response-to")})]
+                      -- ASSIGN  |PARTITIONED|
+                        exchange
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          replicate
+                          -- REPLICATE  |PARTITIONED|
+                            exchange
+                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                              data-scan []<-[$$68, $$s] <- TinySocial.FacebookMessages
+                              -- DATASOURCE_SCAN  |PARTITIONED|
+                                exchange
+                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                  empty-tuple-source
+                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                  exchange
+                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                    project ([$$141, $$69])
+                    -- STREAM_PROJECT  |PARTITIONED|
+                      assign [$$141] <- [cast({"id": $$69, "user": $$t})]
+                      -- ASSIGN  |PARTITIONED|
+                        exchange
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          data-scan []<-[$$69, $$t] <- TinySocial.FacebookUsers
+                          -- DATASOURCE_SCAN  |PARTITIONED|
+                            exchange
+                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                              empty-tuple-source
+                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+              exchange
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                project ([$$140, $$70])
+                -- STREAM_PROJECT  |PARTITIONED|
+                  assign [$$140] <- [cast({"id": $$70, "no_author_id": object-remove($$s, "author-id")})]
+                  -- ASSIGN  |PARTITIONED|
+                    project ([$$70, $$s])
+                    -- STREAM_PROJECT  |PARTITIONED|
+                      assign [$$70, $$s] <- [$$68, $$s]
+                      -- ASSIGN  |PARTITIONED|
+                        exchange
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          replicate
+                          -- REPLICATE  |PARTITIONED|
+                            exchange
+                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                              data-scan []<-[$$68, $$s] <- TinySocial.FacebookMessages
+                              -- DATASOURCE_SCAN  |PARTITIONED|
+                                exchange
+                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                  empty-tuple-source
+                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml b/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml
index 5a544b2..7b875e2 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml
@@ -15007,6 +15007,11 @@
         <output-dir compare="Text">query-ASTERIXDB-1354</output-dir>
       </compilation-unit>
     </test-case>
+    <test-case FilePath="union">
+      <compilation-unit name="union_type_cast">
+        <output-dir compare="Text">union_type_cast</output-dir>
+      </compilation-unit>
+    </test-case>
   </test-group>
   <test-group name="upsert">
     <test-case FilePath="upsert">
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/types/ARecordType.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/types/ARecordType.java
index e256e1b..fd51433 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/types/ARecordType.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/types/ARecordType.java
@@ -25,7 +25,6 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 
 import org.apache.asterix.common.annotations.IRecordTypeAnnotation;
@@ -73,30 +72,21 @@
     private final Set<String> allPossibleAdditionalFieldNames;
 
     /**
-     * @param typeName
-     *            the name of the type
-     * @param fieldNames
-     *            the names of the closed fields
-     * @param fieldTypes
-     *            the types of the closed fields
-     * @param isOpen
-     *            whether the record is open
+     * @param typeName   the name of the type
+     * @param fieldNames the names of the closed fields
+     * @param fieldTypes the types of the closed fields
+     * @param isOpen     whether the record is open
      */
     public ARecordType(String typeName, String[] fieldNames, IAType[] fieldTypes, boolean isOpen) {
         this(typeName, fieldNames, fieldTypes, isOpen, null);
     }
 
     /**
-     * @param typeName
-     *            the name of the type
-     * @param fieldNames
-     *            the names of the closed fields
-     * @param fieldTypes
-     *            the types of the closed fields
-     * @param isOpen
-     *            whether the record is open
-     * @param allPossibleAdditionalFieldNames,
-     *            all possible additional field names.
+     * @param typeName                         the name of the type
+     * @param fieldNames                       the names of the closed fields
+     * @param fieldTypes                       the types of the closed fields
+     * @param isOpen                           whether the record is open
+     * @param allPossibleAdditionalFieldNames, all possible additional field names.
      */
     public ARecordType(String typeName, String[] fieldNames, IAType[] fieldTypes, boolean isOpen,
             Set<String> allPossibleAdditionalFieldNames) {
@@ -189,8 +179,7 @@
     /**
      * Returns the position of the field in the closed schema or -1 if the field does not exist.
      *
-     * @param fieldName
-     *            the name of the field whose position is sought
+     * @param fieldName the name of the field whose position is sought
      * @return the position of the field in the closed schema or -1 if the field does not exist.
      */
     public int getFieldIndex(String fieldName) {
@@ -206,10 +195,8 @@
     }
 
     /**
-     * @param subFieldName
-     *            The full pathname of the child
-     * @param parent
-     *            The type of the parent
+     * @param subFieldName The full pathname of the child
+     * @param parent       The type of the parent
      * @return the type of the child
      */
 
@@ -222,8 +209,7 @@
     }
 
     /**
-     * @param subFieldName
-     *            The full pathname of the child
+     * @param subFieldName The full pathname of the child
      * @return the type of the child
      * @throws AsterixException
      */
@@ -248,9 +234,7 @@
     }
 
     /**
-     *
-     * @param subFieldName
-     *            The full pathname of the field
+     * @param subFieldName The full pathname of the field
      * @return The nullability of the field
      * @throws AlgebricksException
      */
@@ -283,10 +267,9 @@
     /**
      * Returns the field type of the field name if it exists, otherwise null.
      *
-     * @param fieldName
-     *            the fieldName whose type is sought
+     * @param fieldName the fieldName whose type is sought
      * @return the field type of the field name if it exists, otherwise null
-     *         NOTE: this method doesn't work for nested fields
+     * NOTE: this method doesn't work for nested fields
      */
     public IAType getFieldType(String fieldName) {
         int fieldPos = getFieldIndex(fieldName);
@@ -299,8 +282,7 @@
     /**
      * Returns true or false indicating whether or not a field is closed.
      *
-     * @param fieldName
-     *            the name of the field to check
+     * @param fieldName the name of the field to check
      * @return true if fieldName is a closed field, otherwise false
      */
     public boolean isClosedField(String fieldName) {
@@ -360,8 +342,7 @@
         }
         ARecordType rt = (ARecordType) obj;
         return (isOpen == rt.isOpen) && Arrays.deepEquals(fieldNames, rt.fieldNames)
-                && Arrays.deepEquals(fieldTypes, rt.fieldTypes)
-                && Objects.equals(allPossibleAdditionalFieldNames, rt.allPossibleAdditionalFieldNames);
+                && Arrays.deepEquals(fieldTypes, rt.fieldTypes);
     }
 
     @Override
@@ -382,11 +363,7 @@
         ObjectNode type = om.createObjectNode();
         type.put("type", ARecordType.class.getName());
         type.put("name", typeName);
-        if (isOpen) {
-            type.put("open", true);
-        } else {
-            type.put("open", false);
-        }
+        type.put("open", isOpen);
 
         ArrayNode fields = om.createArrayNode();
         for (int i = 0; i < fieldNames.length; i++) {