Support to truncate the fraction part of a decimal number when castin…

…g decimal to an integer (6208)
oap-project · Aug 24, 2023 · 0034e47 · 0034e47
1 parent c2e6d61
commit 0034e47
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Showing 2 changed files with 46 additions and 5 deletions.
diff --git a/velox/expression/CastExpr-inl.h b/velox/expression/CastExpr-inl.h
@@ -269,6 +269,7 @@ VectorPtr CastExpr::applyDecimalToFloatCast(
     const TypePtr& toType) {
   using To = typename TypeTraits<ToKind>::NativeType;
 
+  const auto& queryConfig = context.execCtx()->queryCtx()->queryConfig();
   VectorPtr result;
   context.ensureWritable(rows, toType, result);
   (*result).clearNulls(rows);
@@ -292,6 +293,7 @@ VectorPtr CastExpr::applyDecimalToIntegralCast(
     const TypePtr& fromType,
     const TypePtr& toType) {
   using To = typename TypeTraits<ToKind>::NativeType;
+  const auto& queryConfig = context.execCtx()->queryCtx()->queryConfig();
 
   VectorPtr result;
   context.ensureWritable(rows, toType, result);
@@ -303,11 +305,14 @@ VectorPtr CastExpr::applyDecimalToIntegralCast(
   applyToSelectedNoThrowLocal(context, rows, result, [&](int row) {
     auto value = simpleInput->valueAt(row);
     auto integralPart = value / scaleFactor;
-    auto fractionPart = value % scaleFactor;
-    auto sign = value >= 0 ? 1 : -1;
-    bool needsRoundUp =
-        (scaleFactor != 1) && (sign * fractionPart >= (scaleFactor >> 1));
-    integralPart += needsRoundUp ? sign : 0;
+    if (!queryConfig.isCastToIntByTruncate()) {
+      auto fractionPart = value % scaleFactor;
+      auto sign = value >= 0 ? 1 : -1;
+      bool needsRoundUp =
+          (scaleFactor != 1) && (sign * fractionPart >= (scaleFactor >> 1));
+      integralPart += needsRoundUp ? sign : 0;
+    }
+
     if (integralPart > std::numeric_limits<To>::max() ||
         integralPart < std::numeric_limits<To>::min()) {
       if (setNullInResultAtError()) {

diff --git a/velox/expression/tests/CastExprTest.cpp b/velox/expression/tests/CastExprTest.cpp
@@ -295,6 +295,7 @@ class CastExprTest : public functions::test::CastBaseTest {
 
   template <typename T>
   void testDecimalToIntegralCasts() {
+    setCastIntByTruncate(false);
     auto shortFlat = makeNullableFlatVector<int64_t>(
         {-300,
          -260,
@@ -355,6 +356,41 @@ class CastExprTest : public functions::test::CastBaseTest {
              69,
              72,
              std::nullopt}));
+
+    setCastIntByTruncate(true);
+    testComplexCast(
+        "c0",
+        shortFlat,
+        makeNullableFlatVector<T>(
+            {-3,
+             -2 /*-2.6 truncated to -2*/,
+             -2 /*-2.3 truncated to -2*/,
+             -2,
+             -1,
+             0,
+             55,
+             57 /*57.49 truncated to 57*/,
+             57 /*57.55 truncated to 57*/,
+             69,
+             72,
+             std::nullopt}));
+
+    testComplexCast(
+        "c0",
+        longFlat,
+        makeNullableFlatVector<T>(
+            {-3,
+             -2 /*-2.55 truncated to -2*/,
+             -2 /*-2.45 truncated to -2*/,
+             -2,
+             -1,
+             0,
+             55,
+             55 /* 55.49 truncated to 55*/,
+             55 /* 55.99 truncated to 55*/,
+             69,
+             72,
+             std::nullopt}));
   }
 
   template <typename T>