Add a new implementation for sum for dec type to handle overflow, Add…

… a new DecimalSum and add a analyzer rule and changes to optimizer rule. Add tests

For now the DecimalSum has the code to handle other types, incase we want to put this logic back into Sum after discussion

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala

@@ -240,6 +240,7 @@ class Analyzer(
       ExtractWindowExpressions ::
       GlobalAggregates ::
       ResolveAggregateFunctions ::
+      UseDecimalSum ::
       TimeWindowing ::
       ResolveInlineTables(conf) ::
       ResolveHigherOrderFunctions(v1SessionCatalog) ::
@@ -3066,6 +3067,15 @@ class Analyzer(
     }
   }
 
+  /**
+   * Substitute Sum on decimal type to use DecimalSum implementation as it handles overflow
+   */
+  object UseDecimalSum extends Rule[LogicalPlan] {
+    def apply(plan: LogicalPlan): LogicalPlan = plan.resolveExpressions {
+      case Sum(e) if e.resolved && e.dataType.isInstanceOf[DecimalType] => DecimalSum(e)
+    }
+  }
+
   /** Rule to mostly resolve, normalize and rewrite column names based on case sensitivity. */
   object ResolveAlterTableChanges extends Rule[LogicalPlan] {
     def apply(plan: LogicalPlan): LogicalPlan = plan.resolveOperatorsUp {

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/DecimalSum.scala

@@ -0,0 +1,110 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.catalyst.expressions.aggregate
+
+import org.apache.spark.sql.catalyst.dsl.expressions._
+import org.apache.spark.sql.catalyst.expressions._
+import org.apache.spark.sql.internal.SQLConf
+import org.apache.spark.sql.types._
+
+case class DecimalSum(child: Expression) extends DeclarativeAggregate with ImplicitCastInputTypes {
+
+  override def children: Seq[Expression] = child :: Nil
+
+  override def nullable: Boolean = true
+
+  // Return data type.
+  override def dataType: DataType = resultType
+
+  override def inputTypes: Seq[AbstractDataType] = Seq(NumericType)
+
+  private lazy val resultType = child.dataType match {
+    case DecimalType.Fixed(precision, scale) =>
+      DecimalType.bounded(precision + 10, scale)
+    case _: IntegralType => LongType
+    case _ => DoubleType
+  }
+
+  private lazy val sumDataType = resultType
+
+  private lazy val sum = AttributeReference("sum", sumDataType)()
+  private lazy val overflow = AttributeReference("overflow", BooleanType, false)()
+
+  private lazy val zero = Literal.default(resultType)
+
+  override lazy val aggBufferAttributes = sum :: overflow :: Nil
+
+  override lazy val initialValues: Seq[Expression] = Seq(
+    /* sum = */ Literal.create(null, sumDataType),
+    /* overflow = */ Literal.create(false, BooleanType)
+  )
+
+  override lazy val updateExpressions: Seq[Expression] = {
+    if (child.nullable) {
+      resultType match {
+        case d: DecimalType =>
+          Seq(
+            If(overflow, Literal.create(null, sumDataType), coalesce(
+              CheckOverflow(coalesce(sum, zero) + child.cast(sumDataType), d, true), sum)),
+              overflow ||
+                coalesce(HasOverflow(coalesce(sum, zero) + child.cast(sumDataType), d), false)
+          )
+          case _ => Seq(coalesce(coalesce(sum, zero) + child.cast(sumDataType), sum), false)
+      }
+    } else {
+      resultType match {
+        case d: DecimalType =>
+          Seq(
+            If(overflow, Literal.create(null, sumDataType),
+              CheckOverflow(coalesce(sum, zero) + child.cast(sumDataType), d, true)),
+              overflow ||
+              coalesce(HasOverflow(coalesce(sum, zero) + child.cast(sumDataType), d), false)
+          )
+        case _ => Seq(coalesce(sum, zero) + child.cast(sumDataType), false)
+      }
+    }
+  }
+
+  override lazy val mergeExpressions: Seq[Expression] = {
+    resultType match {
+      case d: DecimalType =>
+        Seq(
+          If(coalesce(overflow.left, false) || coalesce(overflow.right, false),
+            Literal.create(null, d),
+            coalesce(CheckOverflow(coalesce(sum.left, zero) + sum.right, d, true), sum.left)),
+            If(coalesce(overflow.left, false) || coalesce(overflow.right, false),
+            true, HasOverflow(coalesce(sum.left, zero) + sum.right, d))
+        )
+      case _ =>
+        Seq(
+          coalesce(coalesce(sum.left, zero) + sum.right, sum.left),
+          If(coalesce(overflow.left, false) || coalesce(overflow.right, false), true, false)
+        )
+    }
+  }
+
+  override lazy val evaluateExpression: Expression = resultType match {
+    case d: DecimalType =>
+      If(EqualTo(overflow, true),
+        If(!SQLConf.get.ansiEnabled,
+          Literal.create(null, sumDataType),
+          OverflowException(resultType, "Arithmetic Operation overflow")),
+        sum)
+    case _ => sum
+  }
+}

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/Sum.scala

@@ -61,104 +61,38 @@ case class Sum(child: Expression) extends DeclarativeAggregate with ImplicitCast
   private lazy val sumDataType = resultType
 
   private lazy val sum = AttributeReference("sum", sumDataType)()
-  private lazy val overflow = AttributeReference("overflow", BooleanType, false)()
 
   private lazy val zero = Literal.default(sumDataType)
 
-  override lazy val aggBufferAttributes = sum :: overflow :: Nil
+  override lazy val aggBufferAttributes = sum :: Nil
 
   override lazy val initialValues: Seq[Expression] = Seq(
-    /* sum = */ Literal.create(null, sumDataType),
-    /* overflow = */ Literal.create(false, BooleanType)
+    /* sum = */ Literal.create(null, sumDataType)
   )
 
   override lazy val updateExpressions: Seq[Expression] = {
-    if (!SQLConf.get.ansiEnabled) {
-      if (child.nullable) {
-        Seq(
-          /* sum = */
-          coalesce(coalesce(sum, zero) + child.cast(sumDataType), sum),
-          /* overflow = */
-          resultType match {
-            case d: DecimalType =>
-              If(overflow, true,
-                HasOverflow(coalesce(sum, zero) + child.cast(sumDataType), d))
-            case _ => false
-          })
-      } else {
-        Seq(
-          /* sum = */
-          coalesce(sum, zero) + child.cast(sumDataType),
-          /* overflow = */
-          resultType match {
-            case d: DecimalType =>
-              If(overflow, true, HasOverflow(coalesce(sum, zero) + child.cast(sumDataType), d))
-            case _ => false
-          })
-      }
-    } else {
-      if (child.nullable) {
-        Seq(
-          /* sum = */
-          resultType match {
-            case d: DecimalType => coalesce(
-              CheckOverflow(
-                coalesce(sum, zero) + child.cast(sumDataType), d, !SQLConf.get.ansiEnabled), sum)
-            case _ => coalesce(coalesce(sum, zero) + child.cast(sumDataType), sum)
-          },
-          /* overflow = */
-          // overflow flag doesnt need any updates since CheckOverflow will throw exception
-          // if overflow happens
-          false
-        )
-      } else {
-        Seq(
-          /* sum = */
-          resultType match {
-            case d: DecimalType => CheckOverflow(
-              coalesce(sum, zero) + child.cast(sumDataType), d, !SQLConf.get.ansiEnabled)
-            case _ => coalesce(sum, zero) + child.cast(sumDataType)
-          },
-          /* overflow = */
-          false
-        )
-      }
-    }
-  }
-
-  override lazy val mergeExpressions: Seq[Expression] = {
-    if (!SQLConf.get.ansiEnabled) {
+    if (child.nullable) {
       Seq(
         /* sum = */
-        coalesce(coalesce(sum.left, zero) + sum.right, sum.left),
-        /* overflow = */
-        resultType match {
-          case d: DecimalType =>
-            If(coalesce(overflow.left, false) || coalesce(overflow.right, false),
-              true, HasOverflow(coalesce(sum.left, zero) + sum.right, d))
-          case _ =>
-            If(coalesce(overflow.left, false) || coalesce(overflow.right, false), true, false)
-        }
+        coalesce(coalesce(sum, zero) + child.cast(sumDataType), sum)
       )
     } else {
       Seq(
         /* sum = */
-        resultType match {
-          case d: DecimalType =>
-            coalesce(
-              CheckOverflow(coalesce(sum.left, zero) + sum.right, d, !SQLConf.get.ansiEnabled),
-              sum.left)
-          case _ => coalesce(coalesce(sum.left, zero) + sum.right, sum.left)
-        },
-        /* overflow = */
-        If(coalesce(overflow.left, false) || coalesce(overflow.right, false), true, false)
+        coalesce(sum, zero) + child.cast(sumDataType)
       )
     }
   }
 
+  override lazy val mergeExpressions: Seq[Expression] = {
+    Seq(
+      /* sum = */
+      coalesce(coalesce(sum.left, zero) + sum.right, sum.left)
+    )
+  }
+
   override lazy val evaluateExpression: Expression = resultType match {
-    case d: DecimalType =>
-      If(overflow && !SQLConf.get.ansiEnabled, Literal.create(null, resultType), sum)
+    case d: DecimalType => CheckOverflow(sum, d, !SQLConf.get.ansiEnabled)
     case _ => sum
   }
 

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/decimalExpressions.scala

@@ -18,7 +18,8 @@
 package org.apache.spark.sql.catalyst.expressions
 
 import org.apache.spark.sql.catalyst.InternalRow
-import org.apache.spark.sql.catalyst.expressions.codegen.{CodegenContext, EmptyBlock, ExprCode}
+import org.apache.spark.sql.catalyst.expressions.codegen._
+import org.apache.spark.sql.catalyst.expressions.codegen.Block._
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.types._
 
@@ -173,3 +174,23 @@ case class HasOverflow(
 
   override def sql: String = child.sql
 }
+
+case class OverflowException(dtype: DataType, msg: String) extends LeafExpression {
+
+  override def dataType: DataType = dtype
+
+  override def nullable: Boolean = false
+
+  def eval(input: InternalRow): Any = {
+    Decimal.throwArithmeticException(msg)
+  }
+
+  override def doGenCode(ctx: CodegenContext, ev: ExprCode): ExprCode = {
+    ev.copy(code = code"""
+      |${CodeGenerator.javaType(dataType)} ${ev.value} = ${CodeGenerator.defaultValue(dataType)};
+      |${ev.value} = Decimal.throwArithmeticException("${msg}");
+      |""", isNull = FalseLiteral)
+  }
+
+  override def toString: String = "OverflowException"
+}

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala

@@ -1450,7 +1450,7 @@ object DecimalAggregates extends Rule[LogicalPlan] {
   def apply(plan: LogicalPlan): LogicalPlan = plan transform {
     case q: LogicalPlan => q transformExpressionsDown {
       case we @ WindowExpression(ae @ AggregateExpression(af, _, _, _, _), _) => af match {
-        case Sum(e @ DecimalType.Expression(prec, scale)) if prec + 10 <= MAX_LONG_DIGITS =>
+        case DecimalSum(e @ DecimalType.Expression(prec, scale)) if prec + 10 <= MAX_LONG_DIGITS =>
           MakeDecimal(we.copy(windowFunction = ae.copy(aggregateFunction = Sum(UnscaledValue(e)))),
             prec + 10, scale)
 
@@ -1464,7 +1464,7 @@ object DecimalAggregates extends Rule[LogicalPlan] {
         case _ => we
       }
       case ae @ AggregateExpression(af, _, _, _, _) => af match {
-        case Sum(e @ DecimalType.Expression(prec, scale)) if prec + 10 <= MAX_LONG_DIGITS =>
+        case DecimalSum(e @ DecimalType.Expression(prec, scale)) if prec + 10 <= MAX_LONG_DIGITS =>
           MakeDecimal(ae.copy(aggregateFunction = Sum(UnscaledValue(e))), prec + 10, scale)
 
         case Average(e @ DecimalType.Expression(prec, scale)) if prec + 4 <= MAX_DOUBLE_DIGITS =>

sql/catalyst/src/main/scala/org/apache/spark/sql/types/Decimal.scala

@@ -651,4 +651,9 @@ object Decimal {
     override def quot(x: Decimal, y: Decimal): Decimal = x quot y
     override def rem(x: Decimal, y: Decimal): Decimal = x % y
   }
+
+
+  def throwArithmeticException(msg: String): Decimal = {
+    throw new ArithmeticException(msg)
+  }
 }