diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/file/DatasetOperations.java b/asterix-app/src/main/java/edu/uci/ics/asterix/file/DatasetOperations.java
index ce546ee..da64d5f 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/file/DatasetOperations.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/file/DatasetOperations.java
@@ -133,7 +133,7 @@
                                     new IBinaryComparatorFactory[] { null }, AsterixRuntimeComponentsProvider.INSTANCE,
                                     AsterixRuntimeComponentsProvider.INSTANCE,
                                     AsterixRuntimeComponentsProvider.INSTANCE,
-                                    AsterixRuntimeComponentsProvider.INSTANCE);
+                                    AsterixRuntimeComponentsProvider.INSTANCE, null);
                             break;
                         case NGRAM_INVIX:
                         case WORD_INVIX:
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeCreator.java b/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeCreator.java
index 5281ddd..39f5a01 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeCreator.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/file/SecondaryRTreeCreator.java
@@ -8,7 +8,9 @@
 import edu.uci.ics.asterix.formats.nontagged.AqlBinaryComparatorFactoryProvider;
 import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
 import edu.uci.ics.asterix.formats.nontagged.AqlTypeTraitProvider;
+import edu.uci.ics.asterix.metadata.declared.AqlMetadataProvider;
 import edu.uci.ics.asterix.metadata.entities.Index;
+import edu.uci.ics.asterix.om.types.ATypeTag;
 import edu.uci.ics.asterix.om.types.IAType;
 import edu.uci.ics.asterix.om.util.NonTaggedFormatUtil;
 import edu.uci.ics.asterix.translator.DmlTranslator.CompiledCreateIndexStatement;
@@ -38,6 +40,7 @@
 
     protected IPrimitiveValueProviderFactory[] valueProviderFactories;
     protected int numNestedSecondaryKeyFields;
+    protected ATypeTag keyType;
 
     protected SecondaryRTreeCreator(PhysicalOptimizationConfig physOptConf) {
         super(physOptConf);
@@ -52,7 +55,8 @@
                 new LSMRTreeDataflowHelperFactory(valueProviderFactories, RTreePolicyType.RTREE,
                         primaryComparatorFactories, AsterixRuntimeComponentsProvider.INSTANCE,
                         AsterixRuntimeComponentsProvider.INSTANCE, AsterixRuntimeComponentsProvider.INSTANCE,
-                        AsterixRuntimeComponentsProvider.INSTANCE));
+                        AsterixRuntimeComponentsProvider.INSTANCE, AqlMetadataProvider.proposeLinearizer(keyType,
+                                secondaryComparatorFactories.length)));
         AlgebricksPartitionConstraintHelper.setPartitionConstraintInJobSpec(spec, secondaryIndexCreateOp,
                 secondaryPartitionConstraint);
         spec.addRoot(secondaryIndexCreateOp);
@@ -87,6 +91,7 @@
                 + numNestedSecondaryKeyFields];
         ITypeTraits[] secondaryTypeTraits = new ITypeTraits[numNestedSecondaryKeyFields + numPrimaryKeys];
         IAType nestedKeyType = NonTaggedFormatUtil.getNestedSpatialType(spatialType.getTypeTag());
+        keyType = nestedKeyType.getTypeTag();
         for (int i = 0; i < numNestedSecondaryKeyFields; i++) {
             ISerializerDeserializer keySerde = AqlSerializerDeserializerProvider.INSTANCE
                     .getSerializerDeserializer(nestedKeyType);
@@ -125,11 +130,14 @@
         }
 
         // Create secondary RTree bulk load op.
-        TreeIndexBulkLoadOperatorDescriptor secondaryBulkLoadOp = createTreeIndexBulkLoadOp(spec,
-                numNestedSecondaryKeyFields, new LSMRTreeDataflowHelperFactory(valueProviderFactories,
-                        RTreePolicyType.RTREE, primaryComparatorFactories, AsterixRuntimeComponentsProvider.INSTANCE,
+        TreeIndexBulkLoadOperatorDescriptor secondaryBulkLoadOp = createTreeIndexBulkLoadOp(
+                spec,
+                numNestedSecondaryKeyFields,
+                new LSMRTreeDataflowHelperFactory(valueProviderFactories, RTreePolicyType.RTREE,
+                        primaryComparatorFactories, AsterixRuntimeComponentsProvider.INSTANCE,
                         AsterixRuntimeComponentsProvider.INSTANCE, AsterixRuntimeComponentsProvider.INSTANCE,
-                        AsterixRuntimeComponentsProvider.INSTANCE), BTree.DEFAULT_FILL_FACTOR);
+                        AsterixRuntimeComponentsProvider.INSTANCE, AqlMetadataProvider.proposeLinearizer(keyType,
+                                secondaryComparatorFactories.length)), BTree.DEFAULT_FILL_FACTOR);
 
         // Connect the operators.
         spec.connect(new OneToOneConnectorDescriptor(spec), keyProviderOp, 0, primaryScanOp, 0);
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java
index f319730..1f90676 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/declared/AqlMetadataProvider.java
@@ -70,6 +70,7 @@
 import edu.uci.ics.hyracks.algebricks.runtime.operators.std.SinkWriterRuntimeFactory;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -91,6 +92,9 @@
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.dataflow.LSMRTreeDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.dataflow.RTreeSearchOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
+import edu.uci.ics.hyracks.storage.am.rtree.linearize.HilbertDoubleComparatorFactory;
+import edu.uci.ics.hyracks.storage.am.rtree.linearize.ZCurveDoubleComparatorFactory;
+import edu.uci.ics.hyracks.storage.am.rtree.linearize.ZCurveIntComparatorFactory;
 
 public class AqlMetadataProvider implements IMetadataProvider<AqlSourceId, String> {
     private final long txnId;
@@ -403,7 +407,8 @@
                 typeTraits, comparatorFactories, keyFields, new LSMRTreeDataflowHelperFactory(valueProviderFactories,
                         RTreePolicyType.RTREE, primaryComparatorFactories, AsterixRuntimeComponentsProvider.INSTANCE,
                         AsterixRuntimeComponentsProvider.INSTANCE, AsterixRuntimeComponentsProvider.INSTANCE,
-                        AsterixRuntimeComponentsProvider.INSTANCE), false, NoOpOperationCallbackProvider.INSTANCE);
+                        AsterixRuntimeComponentsProvider.INSTANCE, proposeLinearizer(nestedKeyType.getTypeTag(),
+                                comparatorFactories.length)), false, NoOpOperationCallbackProvider.INSTANCE);
         return new Pair<IOperatorDescriptor, AlgebricksPartitionConstraint>(rtreeSearchOp, spPc.second);
     }
 
@@ -768,8 +773,9 @@
                 comparatorFactories, fieldPermutation, indexOp, new LSMRTreeDataflowHelperFactory(
                         valueProviderFactories, RTreePolicyType.RTREE, primaryComparatorFactories,
                         AsterixRuntimeComponentsProvider.INSTANCE, AsterixRuntimeComponentsProvider.INSTANCE,
-                        AsterixRuntimeComponentsProvider.INSTANCE, AsterixRuntimeComponentsProvider.INSTANCE),
-                filterFactory, NoOpOperationCallbackProvider.INSTANCE, txnId);
+                        AsterixRuntimeComponentsProvider.INSTANCE, AsterixRuntimeComponentsProvider.INSTANCE,
+                        proposeLinearizer(nestedKeyType.getTypeTag(), comparatorFactories.length)), filterFactory,
+                NoOpOperationCallbackProvider.INSTANCE, txnId);
         return new Pair<IOperatorDescriptor, AlgebricksPartitionConstraint>(rtreeUpdate, splitsAndConstraint.second);
     }
 
@@ -781,6 +787,20 @@
         return new BTreeNSMInteriorFrameFactory(new TypeAwareTupleWriterFactory(typeTraits));
     }
 
+    public static ILinearizeComparatorFactory proposeLinearizer(ATypeTag keyType, int numKeyFields)
+            throws AlgebricksException {
+        if (numKeyFields / 2 == 2 && (keyType == ATypeTag.DOUBLE)) {
+            return new HilbertDoubleComparatorFactory(2);
+        } else if (keyType == ATypeTag.DOUBLE) {
+            return new ZCurveDoubleComparatorFactory(numKeyFields / 2);
+        } else if (keyType == ATypeTag.INT8 || keyType == ATypeTag.INT16 || keyType == ATypeTag.INT32
+                || keyType == ATypeTag.INT64) {
+            return new ZCurveIntComparatorFactory(numKeyFields / 2);
+        } else {
+            throw new AlgebricksException("Cannot propose linearizer for key with type " + keyType + ".");
+        }
+    }
+
     @Override
     public IFunctionInfo lookupFunction(FunctionIdentifier fid) {
         return AsterixBuiltinFunctions.lookupFunction(fid);