[GitHub] [spark] WangGuangxin commented on a change in pull request #23942: [SPARK-27033][SQL]Add Optimize rule RewriteArithmeticFiltersOnIntegralColumn

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WangGuangxin commented on a change in pull request #23942: [SPARK-27033][SQL]Add Optimize rule RewriteArithmeticFiltersOnIntegralColumn
URL: https://github.com/apache/spark/pull/23942#discussion_r265396580
 
 

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 File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/RewriteArithmeticFiltersOnIntegralColumn.scala
 ##########
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+/*
+ * 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.optimizer
+
+import org.apache.spark.sql.catalyst.expressions._
+import org.apache.spark.sql.catalyst.plans.logical.{Filter, LogicalPlan}
+import org.apache.spark.sql.catalyst.rules.Rule
+import org.apache.spark.sql.types._
+
+/**
+ * Rewrite arithmetic filters on an integral-type (e.g., byte, short, int and long)
+ * column to its equivalent form, leaving attribute alone in a left side, so that
+ * we can push it down to datasources (e.g., Parquet and ORC).
+ *
+ * For example, this rule can optimize a query as follows:
+ * {{{
+ *   SELECT * FROM table WHERE i + 3 = 5
+ *   ==> SELECT * FROM table WHERE i = 5 - 3
+ * }}}
+ *
+ * Then, the [[ConstantFolding]] rule will further optimize it as follows:
+ * {{{
+ *   SELECT * FROM table WHERE i = 2
+ * }}}
+ *
+ * Note:
+ * 1. This rule supports `Add` and `Subtract` in arithmetic expressions.
+ * 2. This rule supports `=`, `>=`, `<=`, `>`, `<`, and `!=` in comparators.
+ * 3. This rule supports integral-type (`byte`, `short`, `int`, `long`) only.
+ *    It doesn't support `float` or `double` because of precision issues.
+  */
+object RewriteArithmeticFiltersOnIntegralColumn extends Rule[LogicalPlan] with PredicateHelper {
+  def apply(plan: LogicalPlan): LogicalPlan = plan transform {
+    case f: Filter =>
+      f transformExpressionsUp {
+        case e @ BinaryComparison(left: BinaryArithmetic, right: Expression)
+            if right.foldable && isDataTypeSafe(left.dataType) =>
+          transformLeft(e, left, right)
+        case e @ BinaryComparison(left: Expression, right: BinaryArithmetic)
+            if left.foldable && isDataTypeSafe(right.dataType) =>
+          transformRight(e, left, right)
+      }
+  }
+
+  private def transformLeft(
+      bc: BinaryComparison,
+      left: BinaryArithmetic,
+      right: Expression): Expression = {
+    left match {
+      case Add(ar: AttributeReference, e) if e.foldable && isOptSafe(Subtract(right, e)) =>
+        bc.makeCopy(Array(ar, Subtract(right, e)))
+      case Add(e, ar: AttributeReference) if e.foldable && isOptSafe(Subtract(right, e)) =>
+        bc.makeCopy(Array(ar, Subtract(right, e)))
+      case Subtract(ar: AttributeReference, e) if e.foldable && isOptSafe(Add(right, e)) =>
+        bc.makeCopy(Array(ar, Add(right, e)))
+      case Subtract(e, ar: AttributeReference) if e.foldable && isOptSafe(Subtract(e, right)) =>
+        bc.makeCopy(Array(Subtract(e, right), ar))
+      case _ => bc
+    }
+  }
+
+  private def transformRight(
+      bc: BinaryComparison,
+      left: Expression,
+      right: BinaryArithmetic): Expression = {
+    right match {
+      case Add(ar: AttributeReference, e) if e.foldable && isOptSafe(Subtract(left, e)) =>
+        bc.makeCopy(Array(Subtract(left, e), ar))
+      case Add(e, ar: AttributeReference) if e.foldable && isOptSafe(Subtract(left, e)) =>
+        bc.makeCopy(Array(Subtract(left, e), ar))
+      case Subtract(ar: AttributeReference, e) if e.foldable && isOptSafe(Add(left, e)) =>
+        bc.makeCopy(Array(Add(left, e), ar))
+      case Subtract(e, ar: AttributeReference) if e.foldable && isOptSafe(Subtract(e, left)) =>
+        bc.makeCopy(Array(ar, Subtract(e, left)))
+      case _ => bc
+    }
+  }
+
+  private def isDataTypeSafe(dataType: DataType): Boolean = dataType match {
+    case ByteType | ShortType | IntegerType | LongType => true
+    case _ => false
+  }
+
+  private def isOptSafe(e: BinaryArithmetic): Boolean = {
+    val leftVal = e.left.eval(EmptyRow)
+    val rightVal = e.right.eval(EmptyRow)
+
+    e match {
+      case Add(_, _) =>
+        e.dataType match {
+          case ByteType =>
+            isAddSafe(leftVal, rightVal, Byte.MinValue, Byte.MaxValue)
+          case ShortType =>
+            isAddSafe(leftVal, rightVal, Short.MinValue, Short.MaxValue)
+          case IntegerType =>
+            isAddSafe(leftVal, rightVal, Int.MinValue, Int.MaxValue)
+          case LongType =>
+            isAddSafe(leftVal, rightVal, Long.MinValue, Long.MaxValue)
+          case _ => false
+        }
+
+      case Subtract(_, _) =>
+        e.dataType match {
+          case ByteType =>
+            isSubtractSafe(leftVal, rightVal, Byte.MinValue, Byte.MaxValue)
+          case ShortType =>
+            isSubtractSafe(leftVal, rightVal, Short.MinValue, Short.MaxValue)
+          case IntegerType =>
+            isSubtractSafe(leftVal, rightVal, Int.MinValue, Int.MaxValue)
+          case LongType =>
+            isSubtractSafe(leftVal, rightVal, Long.MinValue, Long.MaxValue)
+          case _ => false
+        }
+
+      case _ => false
+    }
+  }
+
+  private def isAddSafe[T](left: Any, right: Any, minValue: T, maxValue: T)(
 
 Review comment:
   The check here is to make sure if overflow may occur after rewrite, it will not rewrite this expression.

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