diff --git a/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.cpp b/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.cpp
index 3b38f0deae9ebf178e2878cb4e69b8d54ec7e902..3a096699a05900a83b09bfa0ddca5a7be1fdc4ea 100644
--- a/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.cpp
+++ b/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.cpp
@@ -382,30 +382,27 @@ int copyToOminVec(int maxLen, int vcType, int &ominTypeId, uint64_t &ominVecId,
     return 1;
 }
 
-int copyToOminDecimalVec(int vcType, int &ominTypeId, uint64_t &ominVecId, orc::ColumnVectorBatch *field)
+int copyToOmniDecimalVec(int precision, int &ominTypeId, uint64_t &ominVecId, orc::ColumnVectorBatch *field)
 {
     VectorAllocator *allocator = VectorAllocator::GetGlobalAllocator();
-    if (vcType > 18) {
+    if (precision > 18) {
         ominTypeId = static_cast<int>(OMNI_DECIMAL128);
         orc::Decimal128VectorBatch *lvb = dynamic_cast<orc::Decimal128VectorBatch *>(field);
         FixedWidthVector<OMNI_DECIMAL128> *originalVector =
             new FixedWidthVector<OMNI_DECIMAL128>(allocator, lvb->numElements);
         for (int i = 0; i < lvb->numElements; i++) {
             if (lvb->notNull.data()[i]) {
-                bool wasNegative = false;
                 int64_t highbits = lvb->values.data()[i].getHighBits();
                 uint64_t lowbits = lvb->values.data()[i].getLowBits();
-                uint64_t high = 0;
-                uint64_t low = 0;
-                if (highbits < 0) {
-                    low = ~lowbits + 1;
-                    high = static_cast<uint64_t>(~highbits);
-                    if (low == 0) {
-                        high += 1;
+                if (highbits < 0) { // int128's 2s' complement code
+                    lowbits = ~lowbits + 1; // 2s' complement code
+                    highbits = ~highbits; //1s' complement code
+                    if (lowbits == 0) {
+                        highbits += 1; // carry a number as in adding
                     }
-                    highbits = high | ((uint64_t)1 << 63);
+                    highbits ^= ((uint64_t)1 << 63);
                 }
-                Decimal128 d128(highbits, low);
+                Decimal128 d128(highbits, lowbits);
                 originalVector->SetValue(i, d128);
             } else {
                 originalVector->SetValueNull(i);
@@ -450,7 +447,7 @@ JNIEXPORT jlong JNICALL Java_com_huawei_boostkit_spark_jni_OrcColumnarBatchJniRe
                 if (vcType != orc::TypeKind::DECIMAL) {
                     copyToOminVec(maxLen, vcType, ominTypeId, ominVecId, root->fields[id]);
                 } else {
-                    copyToOminDecimalVec(baseTp.getSubtype(id)->getPrecision(), ominTypeId, ominVecId,
+                    copyToOmniDecimalVec(baseTp.getSubtype(id)->getPrecision(), ominTypeId, ominVecId,
                         root->fields[id]);
                 }
             } catch (omniruntime::exception::OmniException &e) {
@@ -550,4 +547,4 @@ JNIEXPORT jlong JNICALL Java_com_huawei_boostkit_spark_jni_OrcColumnarBatchJniRe
     rowReaderPtr->next(*columnVectorBatch);
     jlong rows = columnVectorBatch->numElements;
     return rows;
-}
\ No newline at end of file
+}
diff --git a/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.h b/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.h
index 5d05f73471a014de14fe870ec602570b73110d84..d8a5b122226d1ac9a60b810ab0e93bd63f1f0d9d 100644
--- a/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.h
+++ b/omnioperator/omniop-spark-extension/cpp/src/jni/OrcColumnarBatchJniReader.h
@@ -142,6 +142,8 @@ int buildLeafs(int leafOp, std::vector<orc::Literal> &litList, orc::Literal &lit
 
 int copyToOminVec(int maxLen, int vcType, int &ominTypeId, uint64_t &ominVecId, orc::ColumnVectorBatch *field);  
 
+int copyToOmniDecimalVec(int precision, int &ominTypeId, uint64_t &ominVecId, orc::ColumnVectorBatch *field);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/omnioperator/omniop-spark-extension/java/src/main/scala/org/apache/spark/sql/execution/ColumnarFileSourceScanExec.scala b/omnioperator/omniop-spark-extension/java/src/main/scala/org/apache/spark/sql/execution/ColumnarFileSourceScanExec.scala
index f1fb7f99a662e7fcda92e8836bff6dd5e5ffae69..845262a056060cea138bd2467256a92b7bafa523 100644
--- a/omnioperator/omniop-spark-extension/java/src/main/scala/org/apache/spark/sql/execution/ColumnarFileSourceScanExec.scala
+++ b/omnioperator/omniop-spark-extension/java/src/main/scala/org/apache/spark/sql/execution/ColumnarFileSourceScanExec.scala
@@ -373,13 +373,7 @@ abstract class BaseColumnarFileSourceScanExec(
   def buildCheck(): Unit = {
     output.zipWithIndex.foreach {
       case (attr, i) =>
-         sparkTypeToOmniType(attr.dataType, attr.metadata)
-         if (attr.dataType.isInstanceOf[DecimalType]) {
-           val dt = attr.dataType.asInstanceOf[DecimalType]
-           if (!DecimalType.is64BitDecimalType(dt)) {
-             throw new UnsupportedOperationException(s"ColumnarTableScan is not supported for type:${dt}");
-           }
-         }
+        sparkTypeToOmniType(attr.dataType, attr.metadata)
     }
   }