Add comment for Uint64

NVIDIA · Dec 21, 2021 · 85e4ae1 · 85e4ae1
1 parent 0e3ad04
commit 85e4ae1
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/sql-plugin/src/main/scala/com/nvidia/spark/rapids/GpuParquetScanBase.scala b/sql-plugin/src/main/scala/com/nvidia/spark/rapids/GpuParquetScanBase.scala
@@ -797,6 +797,10 @@ trait ParquetPartitionReaderBase extends Logging with Arm with ScanWithMetrics
   }
 
   def needDecimalCast(cv: ColumnView, dt: DataType): Boolean = {
+    // UINT64 is casted to Decimal(20,0) by Spark to accommodate
+    // the largest possible values this type can take. Other Unsigned data types are converted to
+    // basic types like LongType, this is analogous to that except we spill over to large
+    // decimal/ints.
     cv.getType.isDecimalType && !GpuColumnVector.getNonNestedRapidsType(dt).equals(cv.getType()) ||
       cv.getType.equals(DType.UINT64)
   }