[SPARK-27747][SQL] add a logical plan link in the physical plan

It's pretty useful if we can convert a physical plan back to a logical plan, e.g., in apache#24389

This PR introduces a new feature to `TreeNode`, which allows `TreeNode` to carry some extra information via a mutable map, and keep the information when it's copied.

The planner leverages this feature to put the logical plan into the physical plan.

a test suite that runs all TPCDS queries and checks that some common physical plans contain the corresponding logical plans.

Closes apache#24626 from cloud-fan/link.

Lead-authored-by: Wenchen Fan <wenchen@databricks.com>
Co-authored-by: Peng Bo <bo.peng1019@gmail.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>

Author: 2 people

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/basicLogicalOperators.scala

@@ -988,7 +988,11 @@ case class OneRowRelation() extends LeafNode {
   override def computeStats(): Statistics = Statistics(sizeInBytes = 1)
 
   /** [[org.apache.spark.sql.catalyst.trees.TreeNode.makeCopy()]] does not support 0-arg ctor. */
-  override def makeCopy(newArgs: Array[AnyRef]): OneRowRelation = OneRowRelation()
+  override def makeCopy(newArgs: Array[AnyRef]): OneRowRelation = {
+    val newCopy = OneRowRelation()
+    newCopy.tags ++= this.tags
+    newCopy
+  }
 }
 
 /** A logical plan for `dropDuplicates`. */

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala

@@ -19,7 +19,7 @@ package org.apache.spark.sql.catalyst.trees
 
 import java.util.UUID
 
-import scala.collection.Map
+import scala.collection.{mutable, Map}
 import scala.reflect.ClassTag
 
 import org.apache.commons.lang3.ClassUtils
@@ -74,13 +74,23 @@ object CurrentOrigin {
   }
 }
 
+// The name of the tree node tag. This is preferred over using string directly, as we can easily
+// find all the defined tags.
+case class TreeNodeTagName(name: String)
+
 // scalastyle:off
 abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
 // scalastyle:on
   self: BaseType =>
 
   val origin: Origin = CurrentOrigin.get
 
+  /**
+   * A mutable map for holding auxiliary information of this tree node. It will be carried over
+   * when this node is copied via `makeCopy`, or transformed via `transformUp`/`transformDown`.
+   */
+  val tags: mutable.Map[TreeNodeTagName, Any] = mutable.Map.empty
+
   /**
    * Returns a Seq of the children of this node.
    * Children should not change. Immutability required for containsChild optimization
@@ -264,6 +274,8 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
     if (this fastEquals afterRule) {
       mapChildren(_.transformDown(rule))
     } else {
+      // If the transform function replaces this node with a new one, carry over the tags.
+      afterRule.tags ++= this.tags
       afterRule.mapChildren(_.transformDown(rule))
     }
   }
@@ -277,7 +289,7 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
    */
   def transformUp(rule: PartialFunction[BaseType, BaseType]): BaseType = {
     val afterRuleOnChildren = mapChildren(_.transformUp(rule))
-    if (this fastEquals afterRuleOnChildren) {
+    val newNode = if (this fastEquals afterRuleOnChildren) {
       CurrentOrigin.withOrigin(origin) {
         rule.applyOrElse(this, identity[BaseType])
       }
@@ -286,6 +298,9 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
         rule.applyOrElse(afterRuleOnChildren, identity[BaseType])
       }
     }
+    // If the transform function replaces this node with a new one, carry over the tags.
+    newNode.tags ++= this.tags
+    newNode
   }
 
   /**
@@ -404,7 +419,9 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
 
     try {
       CurrentOrigin.withOrigin(origin) {
-        defaultCtor.newInstance(allArgs.toArray: _*).asInstanceOf[BaseType]
+        val res = defaultCtor.newInstance(allArgs.toArray: _*).asInstanceOf[BaseType]
+        res.tags ++= this.tags
+        res
       }
     } catch {
       case e: java.lang.IllegalArgumentException =>

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/trees/TreeNodeSuite.scala

@@ -595,4 +595,55 @@ class TreeNodeSuite extends SparkFunSuite {
     val expected = Coalesce(Stream(Literal(1), Literal(3)))
     assert(result === expected)
   }
+
+  test("tags will be carried over after copy & transform") {
+    withClue("makeCopy") {
+      val node = Dummy(None)
+      node.tags += TreeNodeTagName("test") -> "a"
+      val copied = node.makeCopy(Array(Some(Literal(1))))
+      assert(copied.tags(TreeNodeTagName("test")) == "a")
+    }
+
+    def checkTransform(
+        sameTypeTransform: Expression => Expression,
+        differentTypeTransform: Expression => Expression): Unit = {
+      val child = Dummy(None)
+      child.tags += TreeNodeTagName("test") -> "child"
+      val node = Dummy(Some(child))
+      node.tags += TreeNodeTagName("test") -> "parent"
+
+      val transformed = sameTypeTransform(node)
+      // Both the child and parent keep the tags
+      assert(transformed.tags(TreeNodeTagName("test")) == "parent")
+      assert(transformed.children.head.tags(TreeNodeTagName("test")) == "child")
+
+      val transformed2 = differentTypeTransform(node)
+      // Both the child and parent keep the tags, even if we transform the node to a new one of
+      // different type.
+      assert(transformed2.tags(TreeNodeTagName("test")) == "parent")
+      assert(transformed2.children.head.tags.contains(TreeNodeTagName("test")))
+    }
+
+    withClue("transformDown") {
+      checkTransform(
+        sameTypeTransform = _ transformDown {
+          case Dummy(None) => Dummy(Some(Literal(1)))
+        },
+        differentTypeTransform = _ transformDown {
+          case Dummy(None) => Literal(1)
+
+        })
+    }
+
+    withClue("transformUp") {
+      checkTransform(
+        sameTypeTransform = _ transformUp {
+          case Dummy(None) => Dummy(Some(Literal(1)))
+        },
+        differentTypeTransform = _ transformUp {
+          case Dummy(None) => Literal(1)
+
+        })
+    }
+  }
 }

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkPlan.scala

@@ -20,7 +20,6 @@ package org.apache.spark.sql.execution
 import java.io.{ByteArrayInputStream, ByteArrayOutputStream, DataInputStream, DataOutputStream}
 
 import scala.collection.mutable.ArrayBuffer
-import scala.concurrent.ExecutionContext
 
 import org.codehaus.commons.compiler.CompileException
 import org.codehaus.janino.InternalCompilerException
@@ -35,9 +34,15 @@ import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.expressions.codegen.{Predicate => GenPredicate, _}
 import org.apache.spark.sql.catalyst.plans.QueryPlan
 import org.apache.spark.sql.catalyst.plans.physical._
+import org.apache.spark.sql.catalyst.trees.TreeNodeTagName
 import org.apache.spark.sql.execution.metric.SQLMetric
 import org.apache.spark.sql.types.DataType
-import org.apache.spark.util.ThreadUtils
+
+object SparkPlan {
+  // a TreeNode tag in SparkPlan, to carry its original logical plan. The planner will add this tag
+  // when converting a logical plan to a physical plan.
+  val LOGICAL_PLAN_TAG_NAME = TreeNodeTagName("logical_plan")
+}
 
 /**
  * The base class for physical operators.

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala

@@ -63,6 +63,17 @@ case class PlanLater(plan: LogicalPlan) extends LeafExecNode {
 abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
   self: SparkPlanner =>
 
+  override def plan(plan: LogicalPlan): Iterator[SparkPlan] = {
+    super.plan(plan).map { p =>
+      val logicalPlan = plan match {
+        case ReturnAnswer(rootPlan) => rootPlan
+        case _ => plan
+      }
+      p.tags += SparkPlan.LOGICAL_PLAN_TAG_NAME -> logicalPlan
+      p
+    }
+  }
+
   /**
    * Plans special cases of limit operators.
    */

sql/core/src/test/scala/org/apache/spark/sql/execution/LogicalPlanTagInSparkPlanSuite.scala

@@ -0,0 +1,133 @@
+/*
+ * 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.execution
+
+import scala.reflect.ClassTag
+
+import org.apache.spark.sql.TPCDSQuerySuite
+import org.apache.spark.sql.catalyst.expressions.aggregate.{AggregateExpression, Complete, Final}
+import org.apache.spark.sql.catalyst.plans.QueryPlan
+import org.apache.spark.sql.catalyst.plans.logical.{Aggregate, Generate, Join, LocalRelation, LogicalPlan, Range, Sample, Union, Window}
+import org.apache.spark.sql.execution.aggregate.{HashAggregateExec, ObjectHashAggregateExec, SortAggregateExec}
+import org.apache.spark.sql.execution.columnar.{InMemoryRelation, InMemoryTableScanExec}
+import org.apache.spark.sql.execution.datasources.LogicalRelation
+import org.apache.spark.sql.execution.datasources.v2.{BatchScanExec, DataSourceV2Relation}
+import org.apache.spark.sql.execution.exchange.{BroadcastExchangeExec, ReusedExchangeExec, ShuffleExchangeExec}
+import org.apache.spark.sql.execution.joins._
+import org.apache.spark.sql.execution.window.WindowExec
+
+class LogicalPlanTagInSparkPlanSuite extends TPCDSQuerySuite {
+
+  override protected def checkGeneratedCode(plan: SparkPlan): Unit = {
+    super.checkGeneratedCode(plan)
+    checkLogicalPlanTag(plan)
+  }
+
+  private def isFinalAgg(aggExprs: Seq[AggregateExpression]): Boolean = {
+    // TODO: aggregate node without aggregate expressions can also be a final aggregate, but
+    // currently the aggregate node doesn't have a final/partial flag.
+    aggExprs.nonEmpty && aggExprs.forall(ae => ae.mode == Complete || ae.mode == Final)
+  }
+
+  // A scan plan tree is a plan tree that has a leaf node under zero or more Project/Filter nodes.
+  private def isScanPlanTree(plan: SparkPlan): Boolean = plan match {
+    case p: ProjectExec => isScanPlanTree(p.child)
+    case f: FilterExec => isScanPlanTree(f.child)
+    case _: LeafExecNode => true
+    case _ => false
+  }
+
+  private def checkLogicalPlanTag(plan: SparkPlan): Unit = {
+    plan match {
+      case _: HashJoin | _: BroadcastNestedLoopJoinExec | _: CartesianProductExec
+           | _: ShuffledHashJoinExec | _: SortMergeJoinExec =>
+        assertLogicalPlanType[Join](plan)
+
+      // There is no corresponding logical plan for the physical partial aggregate.
+      case agg: HashAggregateExec if isFinalAgg(agg.aggregateExpressions) =>
+        assertLogicalPlanType[Aggregate](plan)
+      case agg: ObjectHashAggregateExec if isFinalAgg(agg.aggregateExpressions) =>
+        assertLogicalPlanType[Aggregate](plan)
+      case agg: SortAggregateExec if isFinalAgg(agg.aggregateExpressions) =>
+        assertLogicalPlanType[Aggregate](plan)
+
+      case _: WindowExec =>
+        assertLogicalPlanType[Window](plan)
+
+      case _: UnionExec =>
+        assertLogicalPlanType[Union](plan)
+
+      case _: SampleExec =>
+        assertLogicalPlanType[Sample](plan)
+
+      case _: GenerateExec =>
+        assertLogicalPlanType[Generate](plan)
+
+      // The exchange related nodes are created after the planning, they don't have corresponding
+      // logical plan.
+      case _: ShuffleExchangeExec | _: BroadcastExchangeExec | _: ReusedExchangeExec =>
+        assert(!plan.tags.contains(SparkPlan.LOGICAL_PLAN_TAG_NAME))
+
+      // The subquery exec nodes are just wrappers of the actual nodes, they don't have
+      // corresponding logical plan.
+      case _: SubqueryExec | _: ReusedSubqueryExec =>
+        assert(!plan.tags.contains(SparkPlan.LOGICAL_PLAN_TAG_NAME))
+
+      case _ if isScanPlanTree(plan) =>
+        // The strategies for planning scan can remove or add FilterExec/ProjectExec nodes,
+        // so it's not simple to check. Instead, we only check that the origin LogicalPlan
+        // contains the corresponding leaf node of the SparkPlan.
+        // a strategy might remove the filter if it's totally pushed down, e.g.:
+        //   logical = Project(Filter(Scan A))
+        //   physical = ProjectExec(ScanExec A)
+        // we only check that leaf modes match between logical and physical plan.
+        val logicalLeaves = getLogicalPlan(plan).collectLeaves()
+        val physicalLeaves = plan.collectLeaves()
+        assert(logicalLeaves.length == 1)
+        assert(physicalLeaves.length == 1)
+        physicalLeaves.head match {
+          case _: RangeExec => logicalLeaves.head.isInstanceOf[Range]
+          case _: DataSourceScanExec => logicalLeaves.head.isInstanceOf[LogicalRelation]
+          case _: InMemoryTableScanExec => logicalLeaves.head.isInstanceOf[InMemoryRelation]
+          case _: LocalTableScanExec => logicalLeaves.head.isInstanceOf[LocalRelation]
+          case _: ExternalRDDScanExec[_] => logicalLeaves.head.isInstanceOf[ExternalRDD[_]]
+          case _: BatchScanExec => logicalLeaves.head.isInstanceOf[DataSourceV2Relation]
+          case _ =>
+        }
+        // Do not need to check the children recursively.
+        return
+
+      case _ =>
+    }
+
+    plan.children.foreach(checkLogicalPlanTag)
+    plan.subqueries.foreach(checkLogicalPlanTag)
+  }
+
+  private def getLogicalPlan(node: SparkPlan): LogicalPlan = {
+    assert(node.tags.contains(SparkPlan.LOGICAL_PLAN_TAG_NAME),
+      node.getClass.getSimpleName + " does not have a logical plan link")
+    node.tags(SparkPlan.LOGICAL_PLAN_TAG_NAME).asInstanceOf[LogicalPlan]
+  }
+
+  private def assertLogicalPlanType[T <: LogicalPlan : ClassTag](node: SparkPlan): Unit = {
+    val logicalPlan = getLogicalPlan(node)
+    val expectedCls = implicitly[ClassTag[T]].runtimeClass
+    assert(expectedCls == logicalPlan.getClass)
+  }
+}