diff --git a/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/ColumnManagerFactory.java b/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/ColumnManagerFactory.java
index cfd5143..2780f92 100644
--- a/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/ColumnManagerFactory.java
+++ b/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/ColumnManagerFactory.java
@@ -26,6 +26,7 @@
 import org.apache.asterix.column.operation.lsm.load.LoadColumnTupleReaderWriterFactory;
 import org.apache.asterix.column.operation.lsm.merge.MergeColumnTupleReaderWriterFactory;
 import org.apache.asterix.om.types.ARecordType;
+import org.apache.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.api.io.IJsonSerializable;
 import org.apache.hyracks.api.io.IPersistedResourceRegistry;
@@ -71,8 +72,10 @@
     }
 
     @Override
-    public AbstractColumnTupleReaderWriterFactory getLoadColumnTupleReaderWriterFactory() {
-        return new LoadColumnTupleReaderWriterFactory(pageSize, maxTupleCount, tolerance, maxLeafNodeSize);
+    public AbstractColumnTupleReaderWriterFactory getLoadColumnTupleReaderWriterFactory(
+            IBinaryComparatorFactory[] cmpFactories) {
+        return new LoadColumnTupleReaderWriterFactory(pageSize, maxTupleCount, tolerance, maxLeafNodeSize,
+                cmpFactories);
     }
 
     @Override
diff --git a/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleReaderWriterFactory.java b/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleReaderWriterFactory.java
index dec2ec3..7fc6fbd 100644
--- a/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleReaderWriterFactory.java
+++ b/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleReaderWriterFactory.java
@@ -20,20 +20,24 @@
 
 import org.apache.asterix.column.operation.lsm.flush.FlushColumnMetadata;
 import org.apache.asterix.column.operation.lsm.flush.FlushColumnTupleReaderWriterFactory;
+import org.apache.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import org.apache.hyracks.storage.am.lsm.btree.column.api.AbstractColumnTupleWriter;
 import org.apache.hyracks.storage.am.lsm.btree.column.api.IColumnMetadata;
+import org.apache.hyracks.storage.common.MultiComparator;
 
 public class LoadColumnTupleReaderWriterFactory extends FlushColumnTupleReaderWriterFactory {
     private static final long serialVersionUID = -7583574057314353873L;
+    private final IBinaryComparatorFactory[] cmpFactories;
 
     public LoadColumnTupleReaderWriterFactory(int pageSize, int maxNumberOfTuples, double tolerance,
-            int maxLeafNodeSize) {
+            int maxLeafNodeSize, IBinaryComparatorFactory[] cmpFactories) {
         super(pageSize, maxNumberOfTuples, tolerance, maxLeafNodeSize);
+        this.cmpFactories = cmpFactories;
     }
 
     @Override
     public AbstractColumnTupleWriter createColumnWriter(IColumnMetadata columnMetadata) {
         return new LoadColumnTupleWriter((FlushColumnMetadata) columnMetadata, pageSize, maxNumberOfTuples, tolerance,
-                maxLeafNodeSize);
+                maxLeafNodeSize, MultiComparator.create(cmpFactories));
     }
 }
diff --git a/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleWriter.java b/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleWriter.java
index e47b210..ca14000 100644
--- a/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleWriter.java
+++ b/asterixdb/asterix-column/src/main/java/org/apache/asterix/column/operation/lsm/load/LoadColumnTupleWriter.java
@@ -20,17 +20,35 @@
 
 import org.apache.asterix.column.operation.lsm.flush.FlushColumnMetadata;
 import org.apache.asterix.column.operation.lsm.flush.FlushColumnTupleWriter;
+import org.apache.hyracks.api.exceptions.ErrorCode;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
+import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
 import org.apache.hyracks.dataflow.common.data.accessors.ITupleReference;
+import org.apache.hyracks.dataflow.common.data.accessors.PointableTupleReference;
+import org.apache.hyracks.storage.common.MultiComparator;
 
 public class LoadColumnTupleWriter extends FlushColumnTupleWriter {
+    private final PointableTupleReference prevTupleKeys;
+    private final MultiComparator comparator;
+
     public LoadColumnTupleWriter(FlushColumnMetadata columnMetadata, int pageSize, int maxNumberOfTuples,
-            double tolerance, int maxLeafNodeSize) {
+            double tolerance, int maxLeafNodeSize, MultiComparator comparator) {
         super(columnMetadata, pageSize, maxNumberOfTuples, tolerance, maxLeafNodeSize);
+        prevTupleKeys =
+                PointableTupleReference.create(columnMetadata.getNumberOfPrimaryKeys(), ArrayBackedValueStorage::new);
+        this.comparator = comparator;
     }
 
     @Override
     public void writeTuple(ITupleReference tuple) throws HyracksDataException {
+        ensureKeysUniqueness(tuple);
         writeRecord(tuple);
     }
+
+    private void ensureKeysUniqueness(ITupleReference tuple) throws HyracksDataException {
+        if (prevTupleKeys.getFieldLength(0) > 0 && comparator.compare(prevTupleKeys, tuple) == 0) {
+            throw HyracksDataException.create(ErrorCode.DUPLICATE_LOAD_INPUT);
+        }
+        prevTupleKeys.set(tuple);
+    }
 }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/api/IColumnManagerFactory.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/api/IColumnManagerFactory.java
index a2dfbcf..d1b9946 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/api/IColumnManagerFactory.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/api/IColumnManagerFactory.java
@@ -20,6 +20,7 @@
 
 import java.io.Serializable;
 
+import org.apache.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import org.apache.hyracks.api.io.IJsonSerializable;
 import org.apache.hyracks.storage.am.lsm.common.api.ILSMIOOperation.LSMIOOperationType;
 
@@ -31,8 +32,11 @@
 
     /**
      * Get column tuple reader/writer for the {@link LSMIOOperationType#LOAD}
+     *
+     * @param cmpFactories Primary keys comparators' factories
      */
-    AbstractColumnTupleReaderWriterFactory getLoadColumnTupleReaderWriterFactory();
+    AbstractColumnTupleReaderWriterFactory getLoadColumnTupleReaderWriterFactory(
+            IBinaryComparatorFactory[] cmpFactories);
 
     /**
      * Get column tuple reader/writer for the {@link LSMIOOperationType#FLUSH}
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/utils/LSMColumnBTreeUtil.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/utils/LSMColumnBTreeUtil.java
index 6ef0dc6..490fa2e 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/utils/LSMColumnBTreeUtil.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/utils/LSMColumnBTreeUtil.java
@@ -82,7 +82,7 @@
         ITreeIndexFrameFactory mergeLeafFrameFactory = new ColumnBTreeLeafFrameFactory(copyTupleWriterFactory,
                 columnManagerFactory.createMergeColumnTupleReaderWriterFactory());
         ITreeIndexFrameFactory bulkLoadLeafFrameFactory = new ColumnBTreeLeafFrameFactory(bulkLoadTupleWriterFactory,
-                columnManagerFactory.getLoadColumnTupleReaderWriterFactory());
+                columnManagerFactory.getLoadColumnTupleReaderWriterFactory(cmpFactories));
         ITreeIndexFrameFactory insertLeafFrameFactory = new BTreeNSMLeafFrameFactory(insertTupleWriterFactory);
         ITreeIndexFrameFactory deleteLeafFrameFactory = new BTreeNSMLeafFrameFactory(deleteTupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(insertTupleWriterFactory);