diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java
index 5479b56a..f239ba6 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java
@@ -69,10 +69,10 @@
 import org.apache.asterix.om.types.ATypeTag;
 import org.apache.asterix.om.types.AbstractCollectionType;
 import org.apache.asterix.om.types.BuiltinType;
-import org.apache.asterix.om.types.EnumDeserializer;
 import org.apache.asterix.om.types.IAType;
 import org.apache.asterix.om.types.TypeTagUtil;
 import org.apache.asterix.om.util.container.IObjectPool;
+import org.apache.asterix.runtime.evaluators.functions.PointableHelper;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.data.std.api.IPointable;
 import org.apache.hyracks.util.string.UTF8StringReader;
@@ -375,7 +375,6 @@
             jRecord.reset();
             ARecordVisitablePointable recordPointable = pointable;
             List<IVisitablePointable> fieldPointables = recordPointable.getFieldValues();
-            List<IVisitablePointable> fieldTypeTags = recordPointable.getFieldTypeTags();
             List<IVisitablePointable> fieldNames = recordPointable.getFieldNames();
             int index = 0;
             boolean closedPart;
@@ -383,9 +382,7 @@
                 IJObject fieldObject = null;
                 for (IPointable fieldPointable : fieldPointables) {
                     closedPart = index < recordType.getFieldTypes().length;
-                    IPointable tt = fieldTypeTags.get(index);
-                    ATypeTag typeTag =
-                            EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(tt.getByteArray()[tt.getStartOffset()]);
+                    ATypeTag typeTag = PointableHelper.getTypeTag(fieldPointables.get(index));
                     IAType fieldType;
                     fieldType =
                             closedPart ? recordType.getFieldTypes()[index] : TypeTagUtil.getBuiltinTypeByTag(typeTag);
@@ -449,7 +446,6 @@
         public IJObject access(AListVisitablePointable pointable, IObjectPool<IJObject, IAType> objectPool,
                 IAType listType, JObjectPointableVisitor pointableVisitor) throws HyracksDataException {
             List<IVisitablePointable> items = pointable.getItems();
-            List<IVisitablePointable> itemTags = pointable.getItemTags();
             JList list = pointable.ordered() ? new JOrderedList(listType) : new JUnorderedList(listType);
             IJObject listItem;
             for (int iter1 = 0; iter1 < items.size(); iter1++) {
@@ -458,10 +454,7 @@
                 IAType fieldType = ((AbstractCollectionType) listType).getItemType();
                 if (fieldType.getTypeTag() == ATypeTag.ANY) {
                     // Second, if defined type is not available, try to infer it from data
-                    IVisitablePointable itemTagPointable = itemTags.get(iter1);
-                    ATypeTag itemTypeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                            .deserialize(itemTagPointable.getByteArray()[itemTagPointable.getStartOffset()]);
-                    fieldType = TypeTagUtil.getBuiltinTypeByTag(itemTypeTag);
+                    fieldType = TypeTagUtil.getBuiltinTypeByTag(PointableHelper.getTypeTag(itemPointable));
                 }
                 typeInfo.reset(fieldType, fieldType.getTypeTag());
                 switch (typeInfo.getTypeTag()) {
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/msgpack/MsgPackAccessors.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/msgpack/MsgPackAccessors.java
index 6efbb6e..6f097d0 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/msgpack/MsgPackAccessors.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/msgpack/MsgPackAccessors.java
@@ -54,9 +54,9 @@
 import org.apache.asterix.om.types.ATypeTag;
 import org.apache.asterix.om.types.AbstractCollectionType;
 import org.apache.asterix.om.types.BuiltinType;
-import org.apache.asterix.om.types.EnumDeserializer;
 import org.apache.asterix.om.types.IAType;
 import org.apache.asterix.om.types.TypeTagUtil;
+import org.apache.asterix.runtime.evaluators.functions.PointableHelper;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.data.std.api.IPointable;
 import org.apache.hyracks.util.encoding.VarLenIntEncoderDecoder;
@@ -207,7 +207,6 @@
         public static Void access(ARecordVisitablePointable pointable, PyTypeInfo arg,
                 MsgPackPointableVisitor pointableVisitor) throws HyracksDataException {
             List<IVisitablePointable> fieldPointables = pointable.getFieldValues();
-            List<IVisitablePointable> fieldTypeTags = pointable.getFieldTypeTags();
             List<IVisitablePointable> fieldNames = pointable.getFieldNames();
             boolean closedPart;
             int index = 0;
@@ -222,9 +221,7 @@
             try {
                 for (IVisitablePointable fieldPointable : fieldPointables) {
                     closedPart = index < recordType.getFieldTypes().length;
-                    IVisitablePointable tt = fieldTypeTags.get(index);
-                    ATypeTag typeTag =
-                            EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(tt.getByteArray()[tt.getStartOffset()]);
+                    ATypeTag typeTag = PointableHelper.getTypeTag(fieldPointables.get(index));
                     IAType fieldType;
                     fieldType =
                             closedPart ? recordType.getFieldTypes()[index] : TypeTagUtil.getBuiltinTypeByTag(typeTag);
@@ -247,7 +244,6 @@
         public static Void access(AListVisitablePointable pointable, PyTypeInfo arg,
                 MsgPackPointableVisitor pointableVisitor) throws HyracksDataException {
             List<IVisitablePointable> items = pointable.getItems();
-            List<IVisitablePointable> itemTags = pointable.getItemTags();
             DataOutput out = arg.getDataOutput();
             try {
                 out.writeByte(ARRAY32);
@@ -261,10 +257,7 @@
                 IAType fieldType = ((AbstractCollectionType) arg.getType()).getItemType();
                 if (fieldType.getTypeTag() == ATypeTag.ANY) {
                     // Second, if defined type is not available, try to infer it from data
-                    IVisitablePointable itemTagPointable = itemTags.get(iter1);
-                    ATypeTag itemTypeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                            .deserialize(itemTagPointable.getByteArray()[itemTagPointable.getStartOffset()]);
-                    fieldType = TypeTagUtil.getBuiltinTypeByTag(itemTypeTag);
+                    fieldType = TypeTagUtil.getBuiltinTypeByTag(PointableHelper.getTypeTag(itemPointable));
                 }
                 PyTypeInfo fieldTypeInfo = pointableVisitor.getTypeInfo(fieldType, out);
                 itemPointable.accept(pointableVisitor, fieldTypeInfo);
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/AListVisitablePointable.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/AListVisitablePointable.java
index 15766b3..88a81d4 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/AListVisitablePointable.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/AListVisitablePointable.java
@@ -50,8 +50,7 @@
     static IObjectFactory<AListVisitablePointable, IAType> FACTORY =
             type -> new AListVisitablePointable((AbstractCollectionType) type);
 
-    private final List<IVisitablePointable> items = new ArrayList<IVisitablePointable>();
-    private final List<IVisitablePointable> itemTags = new ArrayList<IVisitablePointable>();
+    private final List<IVisitablePointable> items = new ArrayList<>();
     private final PointableAllocator allocator = new PointableAllocator();
 
     private final ResettableByteArrayOutputStream dataBos = new ResettableByteArrayOutputStream();
@@ -87,7 +86,6 @@
     private void reset() {
         allocator.reset();
         items.clear();
-        itemTags.clear();
         dataBos.reset();
     }
 
@@ -109,21 +107,13 @@
             if (typedItemList) {
                 for (int i = 0; i < numberOfitems; i++) {
                     itemLength = NonTaggedFormatUtil.getFieldValueLength(b, itemOffset, itemTag, false);
-                    IVisitablePointable tag = allocator.allocateEmpty();
                     IVisitablePointable item = allocator.allocateFieldValue(itemType);
 
-                    // set item type tag
+                    // set item value including the tag
                     int start = dataBos.size();
                     dataDos.writeByte(itemTag.serialize());
-                    int end = dataBos.size();
-                    tag.set(dataBos.getByteArray(), start, end - start);
-                    itemTags.add(tag);
-
-                    // set item value
-                    start = dataBos.size();
-                    dataDos.writeByte(itemTag.serialize());
                     dataDos.write(b, itemOffset, itemLength);
-                    end = dataBos.size();
+                    int end = dataBos.size();
                     item.set(dataBos.getByteArray(), start, end - start);
                     itemOffset += itemLength;
                     items.add(item);
@@ -132,16 +122,8 @@
                 for (int i = 0; i < numberOfitems; i++) {
                     itemTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(b[itemOffset]);
                     itemLength = NonTaggedFormatUtil.getFieldValueLength(b, itemOffset, itemTag, true) + 1;
-                    IVisitablePointable tag = allocator.allocateEmpty();
                     IVisitablePointable item = allocator.allocateFieldValue(itemTag, b, itemOffset + 1);
 
-                    // set item type tag
-                    int start = dataBos.size();
-                    dataDos.writeByte(itemTag.serialize());
-                    int end = dataBos.size();
-                    tag.set(dataBos.getByteArray(), start, end - start);
-                    itemTags.add(tag);
-
                     // open part field already include the type tag
                     item.set(b, itemOffset, itemLength);
                     itemOffset += itemLength;
@@ -154,18 +136,14 @@
     }
 
     @Override
-    public <R, T> R accept(IVisitablePointableVisitor<R, T> vistor, T tag) throws HyracksDataException {
-        return vistor.visit(this, tag);
+    public <R, T> R accept(IVisitablePointableVisitor<R, T> visitor, T tag) throws HyracksDataException {
+        return visitor.visit(this, tag);
     }
 
     public List<IVisitablePointable> getItems() {
         return items;
     }
 
-    public List<IVisitablePointable> getItemTags() {
-        return itemTags;
-    }
-
     public boolean ordered() {
         return ordered;
     }
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/ARecordVisitablePointable.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/ARecordVisitablePointable.java
index 193ff7d..6637af8 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/ARecordVisitablePointable.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/ARecordVisitablePointable.java
@@ -55,7 +55,6 @@
 
     // access results: field names, field types, and field values
     private final List<IVisitablePointable> fieldNames = new ArrayList<>();
-    private final List<IVisitablePointable> fieldTypeTags = new ArrayList<>();
     private final List<IVisitablePointable> fieldValues = new ArrayList<>();
 
     // pointable allocator
@@ -88,28 +87,12 @@
         String[] fieldNameStrs = inputType.getFieldNames();
         numberOfSchemaFields = fieldTypes.length;
 
-        // initialize the buffer for closed parts(fieldName bytes+ type bytes) +
-        // constant(null bytes)
+        // initialize the buffer for closed parts(fieldName bytes+ type bytes) + constant(null bytes)
         try {
             final DataOutputStream typeDos = new DataOutputStream(typeBos);
             final UTF8StringWriter utf8Writer = new UTF8StringWriter();
             for (int i = 0; i < numberOfSchemaFields; i++) {
-                ATypeTag ftypeTag = fieldTypes[i].getTypeTag();
-
-                if (NonTaggedFormatUtil.isOptional(fieldTypes[i])) {
-                    // optional field: add the embedded non-null type tag
-                    ftypeTag = ((AUnionType) fieldTypes[i]).getActualType().getTypeTag();
-                }
-
-                // add type tag Reference
-                int tagStart = typeBos.size();
-                typeDos.writeByte(ftypeTag.serialize());
-                int tagEnd = typeBos.size();
-                IVisitablePointable typeTagReference = AFlatValuePointable.FACTORY.create(null);
-                typeTagReference.set(typeBos.getByteArray(), tagStart, tagEnd - tagStart);
-                fieldTypeTags.add(typeTagReference);
-
-                // add type name Reference (including a astring type tag)
+                // add type name Reference (including a string type tag)
                 int nameStart = typeBos.size();
                 typeDos.writeByte(ATypeTag.SERIALIZED_STRING_TYPE_TAG);
                 utf8Writer.writeUTF8(fieldNameStrs[i], typeDos);
@@ -147,9 +130,6 @@
         for (int i = fieldNames.size() - 1; i >= numberOfSchemaFields; i--) {
             fieldNames.remove(i);
         }
-        for (int i = fieldTypeTags.size() - 1; i >= numberOfSchemaFields; i--) {
-            fieldTypeTags.remove(i);
-        }
         fieldValues.clear();
     }
 
@@ -239,8 +219,7 @@
                 int numberOfOpenFields = AInt32SerializerDeserializer.getInt(b, openPartOffset);
                 int fieldOffset = openPartOffset + 4 + (8 * numberOfOpenFields);
                 for (int i = 0; i < numberOfOpenFields; i++) {
-                    // set the field name (including a type tag, which is
-                    // astring)
+                    // set the field name (including a type tag, which is a string)
                     int fieldValueLength =
                             NonTaggedFormatUtil.getFieldValueLength(b, fieldOffset, ATypeTag.STRING, false);
                     int fnstart = dataBos.size();
@@ -252,12 +231,7 @@
                     fieldNames.add(fieldName);
                     fieldOffset += fieldValueLength;
 
-                    // set the field type tag
-                    IVisitablePointable fieldTypeTag = allocator.allocateEmpty();
-                    fieldTypeTag.set(b, fieldOffset, 1);
-                    fieldTypeTags.add(fieldTypeTag);
                     typeTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(b[fieldOffset]);
-
                     // set the field value (already including type tag)
                     fieldValueLength = NonTaggedFormatUtil.getFieldValueLength(b, fieldOffset, typeTag, true) + 1;
 
@@ -277,10 +251,6 @@
         return fieldNames;
     }
 
-    public List<IVisitablePointable> getFieldTypeTags() {
-        return fieldTypeTags;
-    }
-
     public List<IVisitablePointable> getFieldValues() {
         return fieldValues;
     }
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/AListCaster.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/AListCaster.java
index 96c7db1..c0e59de 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/AListCaster.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/AListCaster.java
@@ -30,8 +30,8 @@
 import org.apache.asterix.om.pointables.base.IVisitablePointable;
 import org.apache.asterix.om.types.ATypeTag;
 import org.apache.asterix.om.types.AbstractCollectionType;
-import org.apache.asterix.om.types.EnumDeserializer;
 import org.apache.asterix.om.types.IAType;
+import org.apache.asterix.om.utils.PointableHelper;
 import org.apache.asterix.om.utils.ResettableByteArrayOutputStream;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.data.std.api.IPointable;
@@ -61,16 +61,11 @@
             reqItemType = reqType.getItemType();
         }
         dataBos.reset();
-
-        List<IVisitablePointable> itemTags = listAccessor.getItemTags();
         List<IVisitablePointable> items = listAccessor.getItems();
-
         int start = dataBos.size();
         for (int i = 0; i < items.size(); i++) {
-            IVisitablePointable itemTypeTag = itemTags.get(i);
             IVisitablePointable item = items.get(i);
-            ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                    .deserialize(itemTypeTag.getByteArray()[itemTypeTag.getStartOffset()]);
+            ATypeTag typeTag = PointableHelper.getTypeTag(item);
             if (reqItemType == null || reqItemType.getTypeTag().equals(ATypeTag.ANY)) {
                 itemCastResult.setOutType(DefaultOpenFieldType.getDefaultOpenFieldType(typeTag));
             } else {
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/ARecordCaster.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/ARecordCaster.java
index 6dda563..64a7965 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/ARecordCaster.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/cast/ARecordCaster.java
@@ -39,10 +39,10 @@
 import org.apache.asterix.om.types.ATypeTag;
 import org.apache.asterix.om.types.AUnionType;
 import org.apache.asterix.om.types.BuiltinType;
-import org.apache.asterix.om.types.EnumDeserializer;
 import org.apache.asterix.om.types.IAType;
 import org.apache.asterix.om.types.hierachy.ATypeHierarchy;
 import org.apache.asterix.om.utils.NonTaggedFormatUtil;
+import org.apache.asterix.om.utils.PointableHelper;
 import org.apache.asterix.om.utils.ResettableByteArrayOutputStream;
 import org.apache.hyracks.algebricks.common.utils.Pair;
 import org.apache.hyracks.api.dataflow.value.IBinaryComparator;
@@ -63,7 +63,7 @@
     // pointable allocator
     private final PointableAllocator allocator = new PointableAllocator();
     private final List<IVisitablePointable> reqFieldNames = new ArrayList<>();
-    private final List<IVisitablePointable> reqFieldTypeTags = new ArrayList<>();
+    private final List<ATypeTag> reqFieldTypeTags = new ArrayList<>();
     private ARecordType cachedReqType = null;
     private final ResettableByteArrayOutputStream bos = new ResettableByteArrayOutputStream();
     private final DataOutputStream dos = new DataOutputStream(bos);
@@ -104,7 +104,6 @@
     public void castRecord(ARecordVisitablePointable recordAccessor, IPointable castOutResult, ARecordType reqType,
             ACastVisitor visitor) throws HyracksDataException {
         List<IVisitablePointable> fieldNames = recordAccessor.getFieldNames();
-        List<IVisitablePointable> fieldTypeTags = recordAccessor.getFieldTypeTags();
         List<IVisitablePointable> fieldValues = recordAccessor.getFieldValues();
         numInputFields = fieldNames.size();
 
@@ -122,8 +121,8 @@
 
         // clear the previous states
         reset();
-        matchClosedPart(fieldNames, fieldTypeTags);
-        writeOutput(fieldNames, fieldTypeTags, fieldValues, outputDos, visitor);
+        matchClosedPart(fieldNames, fieldValues);
+        writeOutput(fieldNames, fieldValues, outputDos, visitor);
         castOutResult.set(outputBos.getByteArray(), 0, outputBos.size());
     }
 
@@ -166,12 +165,7 @@
                 ftypeTag = ((AUnionType) fieldTypes[i]).getActualType().getTypeTag();
                 optionalFields[i] = true;
             }
-            int tagStart = bos.size();
-            dos.writeByte(ftypeTag.serialize());
-            int tagEnd = bos.size();
-            IVisitablePointable typeTagPointable = allocator.allocateEmpty();
-            typeTagPointable.set(bos.getByteArray(), tagStart, tagEnd - tagStart);
-            reqFieldTypeTags.add(typeTagPointable);
+            reqFieldTypeTags.add(ftypeTag);
 
             // add type name pointable (including a string type tag)
             int nameStart = bos.size();
@@ -191,7 +185,7 @@
         quickSort(reqFieldNamesSortedIndex, reqFieldNames, 0, reqFieldNamesSortedIndex.length - 1);
     }
 
-    private void matchClosedPart(List<IVisitablePointable> fieldNames, List<IVisitablePointable> fieldTypeTags)
+    private void matchClosedPart(List<IVisitablePointable> fieldNames, List<IVisitablePointable> fieldValues)
             throws HyracksDataException {
         int fnStart = 0;
         int reqFnStart = 0;
@@ -204,20 +198,18 @@
             int reqFnPos = reqFieldNamesSortedIndex[reqFnStart];
             int c = compare(fieldNames.get(fnPos), reqFieldNames.get(reqFnPos));
             if (c == 0) {
-                IVisitablePointable fieldTypeTag = fieldTypeTags.get(fnPos);
-                IVisitablePointable reqFieldTypeTag = reqFieldTypeTags.get(reqFnPos);
+                ATypeTag fieldTypeTag = PointableHelper.getTypeTag(fieldValues.get(fnPos));
+                ATypeTag reqFieldTypeTag = reqFieldTypeTags.get(reqFnPos);
+                //TODO(ali): check the last || condition
                 if (fieldTypeTag.equals(reqFieldTypeTag) || (
                 // match the null type of optional field
-                optionalFields[reqFnPos] && (fieldTypeTag.equals(nullTypeTag))
-                        || fieldTypeTag.equals(missingTypeTag))) {
+                optionalFields[reqFnPos] && ((fieldTypeTag == ATypeTag.NULL) || fieldTypeTag == ATypeTag.MISSING))) {
                     fieldPermutation[reqFnPos] = fnPos;
                     openFields[fnPos] = false;
                 } else {
                     // if mismatch, check whether input type can be promoted to the required type
-                    ATypeTag inputTypeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                            .deserialize(fieldTypeTag.getByteArray()[fieldTypeTag.getStartOffset()]);
-                    ATypeTag requiredTypeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                            .deserialize(reqFieldTypeTag.getByteArray()[reqFieldTypeTag.getStartOffset()]);
+                    ATypeTag inputTypeTag = fieldTypeTag;
+                    ATypeTag requiredTypeTag = reqFieldTypeTag;
 
                     if (ATypeHierarchy.canPromote(inputTypeTag, requiredTypeTag)
                             || ATypeHierarchy.canDemote(inputTypeTag, requiredTypeTag)) {
@@ -253,9 +245,7 @@
                 ps.print(":");
 
                 //print the field type
-                IVisitablePointable fieldType = fieldTypeTags.get(i);
-                ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                        .deserialize(fieldType.getByteArray()[fieldType.getStartOffset()]);
+                ATypeTag typeTag = PointableHelper.getTypeTag(fieldValues.get(i));
                 ps.print(typeTag);
 
                 //collect the output message and throw the exception
@@ -276,9 +266,8 @@
         }
     }
 
-    private void writeOutput(List<IVisitablePointable> fieldNames, List<IVisitablePointable> fieldTypeTags,
-            List<IVisitablePointable> fieldValues, DataOutput output, ACastVisitor visitor)
-            throws HyracksDataException {
+    private void writeOutput(List<IVisitablePointable> fieldNames, List<IVisitablePointable> fieldValues,
+            DataOutput output, ACastVisitor visitor) throws HyracksDataException {
         // reset the states of the record builder
         recBuilder.reset(cachedReqType);
         recBuilder.init();
@@ -294,10 +283,10 @@
             // as flat
             if (optionalFields[i]) {
                 //the field is optional in the input record
-                IVisitablePointable fieldTypeTag = pos >= 0 ? fieldTypeTags.get(pos) : null;
-                if (fieldTypeTag == null || fieldTypeTag.equals(missingTypeTag)) {
+                ATypeTag fieldTypeTag = pos >= 0 ? PointableHelper.getTypeTag(fieldValues.get(pos)) : null;
+                if (fieldTypeTag == null || fieldTypeTag == ATypeTag.MISSING) {
                     fieldCastResult.setOutType(BuiltinType.AMISSING);
-                } else if (fieldTypeTag.equals(nullTypeTag)) {
+                } else if (fieldTypeTag == ATypeTag.NULL) {
                     fieldCastResult.setOutType(BuiltinType.ANULL);
                 } else {
                     fieldCastResult.setOutType(((AUnionType) fType).getActualType());
@@ -312,10 +301,7 @@
             if (openFields[i]) {
                 IVisitablePointable name = fieldNames.get(i);
                 IVisitablePointable field = fieldValues.get(i);
-                IVisitablePointable fieldTypeTag = fieldTypeTags.get(i);
-
-                ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                        .deserialize(fieldTypeTag.getByteArray()[fieldTypeTag.getStartOffset()]);
+                ATypeTag typeTag = PointableHelper.getTypeTag(field);
                 fieldCastResult.setOutType(DefaultOpenFieldType.getDefaultOpenFieldType(typeTag));
                 field.accept(visitor, fieldCastResult);
                 recBuilder.addField(name, fieldCastResult.getOutPointable());
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/printer/AListPrinter.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/printer/AListPrinter.java
index 3fd23f7..e5114ec 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/printer/AListPrinter.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/pointables/printer/AListPrinter.java
@@ -25,7 +25,7 @@
 import org.apache.asterix.om.pointables.AListVisitablePointable;
 import org.apache.asterix.om.pointables.base.IVisitablePointable;
 import org.apache.asterix.om.types.ATypeTag;
-import org.apache.asterix.om.types.EnumDeserializer;
+import org.apache.asterix.om.utils.PointableHelper;
 import org.apache.hyracks.algebricks.common.utils.Pair;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 
@@ -47,33 +47,28 @@
 
     public void printList(AListVisitablePointable listAccessor, PrintStream ps, IPrintVisitor visitor)
             throws HyracksDataException {
-        List<IVisitablePointable> itemTags = listAccessor.getItemTags();
         List<IVisitablePointable> items = listAccessor.getItems();
         itemVisitorArg.first = ps;
-
         ps.print(startList);
 
         // print item 0 to n-2
         final int size = items.size();
         for (int i = 0; i < size - 1; i++) {
-            printItem(visitor, itemTags, items, i);
+            printItem(visitor, items, i);
             ps.print(separator);
         }
 
         // print item n-1
         if (size > 0) {
-            printItem(visitor, itemTags, items, size - 1);
+            printItem(visitor, items, size - 1);
         }
 
         ps.print(endList);
     }
 
-    private void printItem(IPrintVisitor visitor, List<IVisitablePointable> itemTags, List<IVisitablePointable> items,
-            int i) throws HyracksDataException {
-        IVisitablePointable itemTypeTag = itemTags.get(i);
+    private void printItem(IPrintVisitor visitor, List<IVisitablePointable> items, int i) throws HyracksDataException {
         IVisitablePointable item = items.get(i);
-        ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER
-                .deserialize(itemTypeTag.getByteArray()[itemTypeTag.getStartOffset()]);
+        ATypeTag typeTag = PointableHelper.getTypeTag(item);
         itemVisitorArg.second = getItemTypeTag(item, typeTag);
         item.accept(visitor, itemVisitorArg);
     }
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/utils/PointableHelper.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/utils/PointableHelper.java
new file mode 100644
index 0000000..547c289
--- /dev/null
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/utils/PointableHelper.java
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ */
+package org.apache.asterix.om.utils;
+
+import org.apache.asterix.om.types.ATypeTag;
+import org.apache.asterix.om.types.EnumDeserializer;
+import org.apache.hyracks.data.std.api.IValueReference;
+
+public class PointableHelper {
+
+    //TODO(ali): should be refactored with the other PointableHelper
+    public static ATypeTag getTypeTag(IValueReference val) {
+        return EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(val.getByteArray()[val.getStartOffset()]);
+    }
+}
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordMergeEvaluator.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordMergeEvaluator.java
index 95003a3..86f74af 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordMergeEvaluator.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordMergeEvaluator.java
@@ -83,8 +83,8 @@
 
     private final RuntimeRecordTypeInfo runtimeRecordTypeInfo = new RuntimeRecordTypeInfo();
     private final DeepEqualAssessor deepEqualAssessor = new DeepEqualAssessor();
-    private ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
-    private DataOutput out = resultStorage.getDataOutput();
+    private final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
+    private final DataOutput out = resultStorage.getDataOutput();
 
     RecordMergeEvaluator(IEvaluatorContext ctx, IScalarEvaluatorFactory[] args, IAType[] argTypes,
             SourceLocation sourceLocation, FunctionIdentifier identifier, boolean isIgnoreDuplicates)
@@ -143,22 +143,21 @@
         for (int i = 0; i < leftRecord.getFieldNames().size(); i++) {
             IVisitablePointable leftName = leftRecord.getFieldNames().get(i);
             IVisitablePointable leftValue = leftRecord.getFieldValues().get(i);
-            IVisitablePointable leftType = leftRecord.getFieldTypeTags().get(i);
+            ATypeTag leftType = PointableHelper.getTypeTag(leftValue);
 
             // Check if a match for the left record exists on the right record
             boolean foundMatch = false;
             for (int j = 0; j < rightRecord.getFieldNames().size(); j++) {
                 IVisitablePointable rightName = rightRecord.getFieldNames().get(j);
                 IVisitablePointable rightValue = rightRecord.getFieldValues().get(j);
-                IVisitablePointable rightType = rightRecord.getFieldTypeTags().get(j);
+                ATypeTag rightType = PointableHelper.getTypeTag(rightValue);
 
                 // Check if same field name and not same value exists (same name and value, just take the left one)
                 if (PointableHelper.isEqual(leftName, rightName, stringBinaryComparator)
                         && !deepEqualAssessor.isEqual(leftValue, rightValue)) {
 
                     // Same name, different value, both of type Record, do nested join
-                    if (PointableHelper.sameType(ATypeTag.OBJECT, rightType)
-                            && PointableHelper.sameType(ATypeTag.OBJECT, leftType)) {
+                    if (ATypeTag.OBJECT == rightType && ATypeTag.OBJECT == leftType) {
                         // We are merging two sub records
                         addFieldToSubRecord(combinedType, leftName, leftValue, rightValue, nestedLevel);
                         foundMatch = true;
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordRemoveFieldsEvalFactory.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordRemoveFieldsEvalFactory.java
index 1a453a7..7ff0dae 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordRemoveFieldsEvalFactory.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/functions/records/RecordRemoveFieldsEvalFactory.java
@@ -145,7 +145,6 @@
 
                 List<IVisitablePointable> fieldNames = srp.getFieldNames();
                 List<IVisitablePointable> fieldValues = srp.getFieldValues();
-                List<IVisitablePointable> fieldTypes = srp.getFieldTypeTags();
 
                 for (int i = 0; i < fieldNames.size(); i++) {
                     IVisitablePointable subRecFieldName = fieldNames.get(i);
@@ -153,10 +152,11 @@
                     if (isValidPath(inputList)) {
                         if (requiredType != null && requiredType.getTypeTag() != ATypeTag.ANY) {
                             addKeptFieldToSubRecord(requiredType, subRecFieldName, fieldValues.get(i),
-                                    fieldTypes.get(i), inputList, nestedLevel);
+                                    PointableHelper.getTypeTag(fieldValues.get(i)), inputList, nestedLevel);
                         } else {
                             addKeptFieldToSubRecord(DefaultOpenFieldType.NESTED_OPEN_RECORD_TYPE, subRecFieldName,
-                                    fieldValues.get(i), fieldTypes.get(i), inputList, nestedLevel);
+                                    fieldValues.get(i), PointableHelper.getTypeTag(fieldValues.get(i)), inputList,
+                                    nestedLevel);
                         }
                     }
                     recordPath.pop();
@@ -164,14 +164,14 @@
             }
 
             private void addKeptFieldToSubRecord(ARecordType requiredType, IVisitablePointable fieldNamePointable,
-                    IVisitablePointable fieldValuePointable, IVisitablePointable fieldTypePointable,
+                    IVisitablePointable fieldValuePointable, ATypeTag fieldTypePointable,
                     AListVisitablePointable inputList, int nestedLevel) throws IOException {
 
                 runtimeRecordTypeInfo.reset(requiredType);
                 int pos = runtimeRecordTypeInfo.getFieldIndex(fieldNamePointable.getByteArray(),
                         fieldNamePointable.getStartOffset() + 1, fieldNamePointable.getLength() - 1);
                 if (pos >= 0) { // Closed field
-                    if (PointableHelper.sameType(ATypeTag.OBJECT, fieldTypePointable)
+                    if (ATypeTag.OBJECT == fieldTypePointable
                             && PointableHelper.sameType(ATypeTag.OBJECT, fieldValuePointable)) {
                         processRecord((ARecordType) TypeComputeUtils.getActualType(requiredType.getFieldTypes()[pos]),
                                 (ARecordVisitablePointable) fieldValuePointable, inputList, nestedLevel + 1);
@@ -182,7 +182,7 @@
                         rbStack.get(nestedLevel).addField(pos, fieldValuePointable);
                     }
                 } else { // Open field
-                    if (PointableHelper.sameType(ATypeTag.OBJECT, fieldTypePointable)) {
+                    if (ATypeTag.OBJECT == fieldTypePointable) {
                         processRecord(null, (ARecordVisitablePointable) fieldValuePointable, inputList,
                                 nestedLevel + 1);
                         tabvs.reset();
@@ -196,12 +196,10 @@
 
             private boolean isValidPath(AListVisitablePointable inputList) throws HyracksDataException {
                 List<IVisitablePointable> items = inputList.getItems();
-                List<IVisitablePointable> typeTags = inputList.getItemTags();
-
                 int pathLen = recordPath.size();
                 for (int i = 0; i < items.size(); i++) {
                     IVisitablePointable item = items.get(i);
-                    if (PointableHelper.sameType(ATypeTag.ARRAY, typeTags.get(i))) {
+                    if (PointableHelper.sameType(ATypeTag.ARRAY, item)) {
                         List<IVisitablePointable> inputPathItems = ((AListVisitablePointable) item).getItems();
 
                         if (pathLen == inputPathItems.size()) {
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/ListDeepEqualityChecker.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/ListDeepEqualityChecker.java
index e510441..e9dbe30 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/ListDeepEqualityChecker.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/ListDeepEqualityChecker.java
@@ -51,11 +51,9 @@
 
         AListVisitablePointable listLeft = (AListVisitablePointable) listPointableLeft;
         List<IVisitablePointable> itemsLeft = listLeft.getItems();
-        List<IVisitablePointable> itemTagTypesLeft = listLeft.getItemTags();
 
         AListVisitablePointable listRight = (AListVisitablePointable) listPointableRight;
         List<IVisitablePointable> itemsRight = listRight.getItems();
-        List<IVisitablePointable> itemTagTypesRight = listRight.getItemTags();
 
         if (itemsLeft.size() != itemsRight.size())
             return false;
@@ -65,23 +63,23 @@
             return false;
 
         if (isOrderedRight) {
-            return processOrderedList(itemsLeft, itemTagTypesLeft, itemsRight, itemTagTypesRight);
+            return processOrderedList(itemsLeft, itemsRight);
         } else {
-            return processUnorderedList(itemsLeft, itemTagTypesLeft, itemsRight, itemTagTypesRight);
+            return processUnorderedList(itemsLeft, itemsRight);
         }
     }
 
-    private boolean processOrderedList(List<IVisitablePointable> itemsLeft, List<IVisitablePointable> itemTagTypesLeft,
-            List<IVisitablePointable> itemsRight, List<IVisitablePointable> itemTagTypesRight)
+    private boolean processOrderedList(List<IVisitablePointable> itemsLeft, List<IVisitablePointable> itemsRight)
             throws HyracksDataException {
         for (int i = 0; i < itemsLeft.size(); i++) {
-            ATypeTag fieldTypeLeft = PointableHelper.getTypeTag(itemTagTypesLeft.get(i));
-            if (fieldTypeLeft.isDerivedType()
-                    && fieldTypeLeft != PointableHelper.getTypeTag(itemTagTypesRight.get(i))) {
+            IVisitablePointable itemLeft = itemsLeft.get(i);
+            IVisitablePointable itemRight = itemsRight.get(i);
+            ATypeTag fieldTypeLeft = PointableHelper.getTypeTag(itemLeft);
+            if (fieldTypeLeft.isDerivedType() && fieldTypeLeft != PointableHelper.getTypeTag(itemRight)) {
                 return false;
             }
-            itemVisitorArg.first = itemsRight.get(i);
-            itemsLeft.get(i).accept(visitor, itemVisitorArg);
+            itemVisitorArg.first = itemRight;
+            itemLeft.accept(visitor, itemVisitorArg);
             if (itemVisitorArg.second == false)
                 return false;
         }
@@ -89,9 +87,8 @@
         return true;
     }
 
-    private boolean processUnorderedList(List<IVisitablePointable> itemsLeft,
-            List<IVisitablePointable> itemTagTypesLeft, List<IVisitablePointable> itemsRight,
-            List<IVisitablePointable> itemTagTypesRight) throws HyracksDataException {
+    private boolean processUnorderedList(List<IVisitablePointable> itemsLeft, List<IVisitablePointable> itemsRight)
+            throws HyracksDataException {
 
         hashMap.clear();
         // Build phase: Add items into hash map, starting with first list.
@@ -105,11 +102,10 @@
             hashMap.put(keyEntry, valEntry);
         }
 
-        return probeHashMap(itemsLeft, itemTagTypesLeft, itemsRight, itemTagTypesRight);
+        return probeHashMap(itemsLeft, itemsRight);
     }
 
-    private boolean probeHashMap(List<IVisitablePointable> itemsLeft, List<IVisitablePointable> itemTagTypesLeft,
-            List<IVisitablePointable> itemsRight, List<IVisitablePointable> itemTagTypesRight)
+    private boolean probeHashMap(List<IVisitablePointable> itemsLeft, List<IVisitablePointable> itemsRight)
             throws HyracksDataException {
         // Probe phase: Probe items from second list
         for (int indexRight = 0; indexRight < itemsRight.size(); indexRight++) {
@@ -126,14 +122,14 @@
             }
 
             int indexLeft = IntegerPointable.getInteger(entry.getBuf(), entry.getOffset());
-            ATypeTag fieldTypeLeft = PointableHelper.getTypeTag(itemTagTypesLeft.get(indexLeft));
-            if (fieldTypeLeft.isDerivedType()
-                    && fieldTypeLeft != PointableHelper.getTypeTag(itemTagTypesRight.get(indexRight))) {
+            IVisitablePointable itemLeft = itemsLeft.get(indexLeft);
+            ATypeTag fieldTypeLeft = PointableHelper.getTypeTag(itemLeft);
+            if (fieldTypeLeft.isDerivedType() && fieldTypeLeft != PointableHelper.getTypeTag(itemRight)) {
                 return false;
             }
 
             itemVisitorArg.first = itemRight;
-            itemsLeft.get(indexLeft).accept(visitor, itemVisitorArg);
+            itemLeft.accept(visitor, itemVisitorArg);
             if (itemVisitorArg.second == false)
                 return false;
         }
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/RecordDeepEqualityChecker.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/RecordDeepEqualityChecker.java
index 1c033e9..f2261e2 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/RecordDeepEqualityChecker.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/visitors/RecordDeepEqualityChecker.java
@@ -79,12 +79,10 @@
             hashMap.put(keyEntry, valEntry);
         }
 
-        return compareValues(recLeft.getFieldTypeTags(), recLeft.getFieldValues(), fieldNamesRight,
-                recRight.getFieldTypeTags(), recRight.getFieldValues());
+        return compareValues(recLeft.getFieldValues(), fieldNamesRight, recRight.getFieldValues());
     }
 
-    private boolean compareValues(List<IVisitablePointable> fieldTypesLeft, List<IVisitablePointable> fieldValuesLeft,
-            List<IVisitablePointable> fieldNamesRight, List<IVisitablePointable> fieldTypesRight,
+    private boolean compareValues(List<IVisitablePointable> fieldValuesLeft, List<IVisitablePointable> fieldNamesRight,
             List<IVisitablePointable> fieldValuesRight) throws HyracksDataException {
 
         // Probe phase: Probe items from second record
@@ -97,12 +95,14 @@
             }
 
             int fieldIdLeft = AInt32SerializerDeserializer.getInt(entry.getBuf(), entry.getOffset());
-            ATypeTag fieldTypeLeft = PointableHelper.getTypeTag(fieldTypesLeft.get(fieldIdLeft));
-            if (fieldTypeLeft.isDerivedType() && fieldTypeLeft != PointableHelper.getTypeTag(fieldTypesRight.get(i))) {
+            IVisitablePointable fieldValLeft = fieldValuesLeft.get(fieldIdLeft);
+            IVisitablePointable fieldValRight = fieldValuesRight.get(i);
+            ATypeTag fieldTypeLeft = PointableHelper.getTypeTag(fieldValLeft);
+            if (fieldTypeLeft.isDerivedType() && fieldTypeLeft != PointableHelper.getTypeTag(fieldValRight)) {
                 return false;
             }
-            nestedVisitorArg.first = fieldValuesRight.get(i);
-            fieldValuesLeft.get(fieldIdLeft).accept(visitor, nestedVisitorArg);
+            nestedVisitorArg.first = fieldValRight;
+            fieldValLeft.accept(visitor, nestedVisitorArg);
             if (nestedVisitorArg.second == false) {
                 return false;
             }