Enable config to check for casting decimals to strings (#4163)

Signed-off-by: Robert (Bobby) Evans <bobby@apache.org>
NVIDIA · Nov 19, 2021 · 88afe19 · 88afe19
1 parent 45898e0
commit 88afe19
Showing 1 changed file with 10 additions and 3 deletions.
diff --git a/sql-plugin/src/main/scala/com/nvidia/spark/rapids/GpuCast.scala b/sql-plugin/src/main/scala/com/nvidia/spark/rapids/GpuCast.scala
@@ -70,9 +70,16 @@ final class CastExprMeta[INPUT <: CastBase](
       case (FloatType | DoubleType, ByteType | ShortType | IntegerType | LongType) if
           doFloatToIntCheck && !conf.isCastFloatToIntegralTypesEnabled =>
         willNotWorkOnGpu(buildTagMessage(RapidsConf.ENABLE_CAST_FLOAT_TO_INTEGRAL_TYPES))
-      case (dt: DecimalType, _: StringType) if dt.precision > DType.DECIMAL64_MAX_PRECISION =>
-        willNotWorkOnGpu(s"decimal to string with a " +
-            s"precision > ${DType.DECIMAL64_MAX_PRECISION} is not supported yet")
+      case (dt: DecimalType, _: StringType) =>
+        if (!conf.isCastDecimalToStringEnabled) {
+          willNotWorkOnGpu("the GPU does not produce the exact same string as Spark produces, " +
+              s"set ${RapidsConf.ENABLE_CAST_DECIMAL_TO_STRING} to true if semantically " +
+              s"equivalent decimal strings are sufficient for your application.")
+        }
+        if (dt.precision > DType.DECIMAL64_MAX_PRECISION) {
+          willNotWorkOnGpu(s"decimal to string with a " +
+              s"precision > ${DType.DECIMAL64_MAX_PRECISION} is not supported yet")
+        }
       case ( _: DecimalType, _: FloatType | _: DoubleType) if !conf.isCastDecimalToFloatEnabled =>
         willNotWorkOnGpu("the GPU will use a different strategy from Java's BigDecimal " +
             "to convert decimal data types to floating point and this can produce results that " +