[SPARK-7067] [SQL] fix bug when use complex nested fields in ORDER BY

This PR is a improvement for #5189.

The resolution rule for ORDER BY is: first resolve based on what comes from the select clause and then fall back on its child only when this fails.

There are 2 steps. First, try to resolve `Sort` in `ResolveReferences` based on select clause, and ignore exceptions. Second, try to resolve `Sort` in `ResolveSortReferences` and add missing projection.

However, the way we resolve `SortOrder` is wrong. We just resolve `UnresolvedAttribute` and use the result to indicate if we can resolve `SortOrder`. But `UnresolvedAttribute` is only part of `GetField` chain(broken by `GetItem`), so we need to go through the whole chain to indicate if we can resolve `SortOrder`.

With this change, we can also avoid re-throw GetField exception in `CheckAnalysis` which is little ugly.

Author: Wenchen Fan <[email protected]>

Closes #5659 from cloud-fan/order-by and squashes the following commits:

cfa79f8 [Wenchen Fan] update test
3245d28 [Wenchen Fan] minor improve
465ee07 [Wenchen Fan] address comment
1fc41a2 [Wenchen Fan] fix SPARK-7067

Author: cloud-fan

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

@@ -336,9 +336,15 @@ class Analyzer(
         }
         j.copy(right = newRight)
 
+      // When resolve `SortOrder`s in Sort based on child, don't report errors as
+      // we still have chance to resolve it based on grandchild
+      case s @ Sort(ordering, global, child) if child.resolved && !s.resolved =>
+        val newOrdering = resolveSortOrders(ordering, child, throws = false)
+        Sort(newOrdering, global, child)
+
       case q: LogicalPlan =>
         logTrace(s"Attempting to resolve ${q.simpleString}")
-        q transformExpressionsUp  {
+        q transformExpressionsUp {
           case u @ UnresolvedAttribute(nameParts) if nameParts.length == 1 &&
             resolver(nameParts(0), VirtualColumn.groupingIdName) &&
             q.isInstanceOf[GroupingAnalytics] =>
@@ -373,6 +379,26 @@ class Analyzer(
       exprs.exists(_.collect { case _: Star => true }.nonEmpty)
   }
 
+  private def resolveSortOrders(ordering: Seq[SortOrder], plan: LogicalPlan, throws: Boolean) = {
+    ordering.map { order =>
+      // Resolve SortOrder in one round.
+      // If throws == false or the desired attribute doesn't exist
+      // (like try to resolve `a.b` but `a` doesn't exist), fail and return the origin one.
+      // Else, throw exception.
+      try {
+        val newOrder = order transformUp {
+          case u @ UnresolvedAttribute(nameParts) =>
+            plan.resolve(nameParts, resolver).getOrElse(u)
+          case UnresolvedExtractValue(child, fieldName) if child.resolved =>
+            ExtractValue(child, fieldName, resolver)
+        }
+        newOrder.asInstanceOf[SortOrder]
+      } catch {
+        case a: AnalysisException if !throws => order
+      }
+    }
+  }
+
   /**
    * In many dialects of SQL it is valid to sort by attributes that are not present in the SELECT
    * clause.  This rule detects such queries and adds the required attributes to the original
@@ -383,13 +409,13 @@ class Analyzer(
     def apply(plan: LogicalPlan): LogicalPlan = plan transformUp {
       case s @ Sort(ordering, global, p @ Project(projectList, child))
           if !s.resolved && p.resolved =>
-        val (resolvedOrdering, missing) = resolveAndFindMissing(ordering, p, child)
+        val (newOrdering, missing) = resolveAndFindMissing(ordering, p, child)
 
         // If this rule was not a no-op, return the transformed plan, otherwise return the original.
         if (missing.nonEmpty) {
           // Add missing attributes and then project them away after the sort.
           Project(p.output,
-            Sort(resolvedOrdering, global,
+            Sort(newOrdering, global,
               Project(projectList ++ missing, child)))
         } else {
           logDebug(s"Failed to find $missing in ${p.output.mkString(", ")}")
@@ -404,19 +430,19 @@ class Analyzer(
         )
 
         // Find sort attributes that are projected away so we can temporarily add them back in.
-        val (resolvedOrdering, unresolved) = resolveAndFindMissing(ordering, a, groupingRelation)
+        val (newOrdering, missingAttr) = resolveAndFindMissing(ordering, a, groupingRelation)
 
         // Find aggregate expressions and evaluate them early, since they can't be evaluated in a
         // Sort.
-        val (withAggsRemoved, aliasedAggregateList) = resolvedOrdering.map {
+        val (withAggsRemoved, aliasedAggregateList) = newOrdering.map {
           case aggOrdering if aggOrdering.collect { case a: AggregateExpression => a }.nonEmpty =>
             val aliased = Alias(aggOrdering.child, "_aggOrdering")()
-            (aggOrdering.copy(child = aliased.toAttribute), aliased :: Nil)
+            (aggOrdering.copy(child = aliased.toAttribute), Some(aliased))
 
-          case other => (other, Nil)
+          case other => (other, None)
         }.unzip
 
-        val missing = unresolved ++ aliasedAggregateList.flatten
+        val missing = missingAttr ++ aliasedAggregateList.flatten
 
         if (missing.nonEmpty) {
           // Add missing grouping exprs and then project them away after the sort.
@@ -429,40 +455,25 @@ class Analyzer(
     }
 
     /**
-     * Given a child and a grandchild that are present beneath a sort operator, returns
-     * a resolved sort ordering and a list of attributes that are missing from the child
-     * but are present in the grandchild.
+     * Given a child and a grandchild that are present beneath a sort operator, try to resolve
+     * the sort ordering and returns it with a list of attributes that are missing from the
+     * child but are present in the grandchild.
      */
     def resolveAndFindMissing(
         ordering: Seq[SortOrder],
         child: LogicalPlan,
         grandchild: LogicalPlan): (Seq[SortOrder], Seq[Attribute]) = {
-      // Find any attributes that remain unresolved in the sort.
-      val unresolved: Seq[Seq[String]] =
-        ordering.flatMap(_.collect { case UnresolvedAttribute(nameParts) => nameParts })
-
-      // Create a map from name, to resolved attributes, when the desired name can be found
-      // prior to the projection.
-      val resolved: Map[Seq[String], NamedExpression] =
-        unresolved.flatMap(u => grandchild.resolve(u, resolver).map(a => u -> a)).toMap
-
+      val newOrdering = resolveSortOrders(ordering, grandchild, throws = true)
       // Construct a set that contains all of the attributes that we need to evaluate the
       // ordering.
-      val requiredAttributes = AttributeSet(resolved.values)
-
+      val requiredAttributes = AttributeSet(newOrdering.filter(_.resolved))
       // Figure out which ones are missing from the projection, so that we can add them and
       // remove them after the sort.
       val missingInProject = requiredAttributes -- child.output
-
-      // Now that we have all the attributes we need, reconstruct a resolved ordering.
-      // It is important to do it here, instead of waiting for the standard resolved as adding
-      // attributes to the project below can actually introduce ambiquity that was not present
-      // before.
-      val resolvedOrdering = ordering.map(_ transform {
-        case u @ UnresolvedAttribute(name) => resolved.getOrElse(name, u)
-      }).asInstanceOf[Seq[SortOrder]]
-
-      (resolvedOrdering, missingInProject.toSeq)
+      // It is important to return the new SortOrders here, instead of waiting for the standard
+      // resolving process as adding attributes to the project below can actually introduce
+      // ambiguity that was not present before.
+      (newOrdering, missingInProject.toSeq)
     }
   }
 

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

@@ -51,14 +51,6 @@ trait CheckAnalysis {
       case operator: LogicalPlan =>
         operator transformExpressionsUp {
           case a: Attribute if !a.resolved =>
-            if (operator.childrenResolved) {
-              a match {
-                case UnresolvedAttribute(nameParts) =>
-                  // Throw errors for specific problems with get field.
-                  operator.resolveChildren(nameParts, resolver, throwErrors = true)
-              }
-            }
-
             val from = operator.inputSet.map(_.name).mkString(", ")
             a.failAnalysis(s"cannot resolve '${a.prettyString}' given input columns $from")
 

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

@@ -50,19 +50,19 @@ abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
    * [[org.apache.spark.sql.catalyst.analysis.UnresolvedRelation UnresolvedRelation]]
    * should return `false`).
    */
-  lazy val resolved: Boolean = !expressions.exists(!_.resolved) && childrenResolved
+  lazy val resolved: Boolean = expressions.forall(_.resolved) && childrenResolved
 
   override protected def statePrefix = if (!resolved) "'" else super.statePrefix
 
   /**
    * Returns true if all its children of this query plan have been resolved.
    */
-  def childrenResolved: Boolean = !children.exists(!_.resolved)
+  def childrenResolved: Boolean = children.forall(_.resolved)
 
   /**
    * Returns true when the given logical plan will return the same results as this logical plan.
    *
-   * Since its likely undecideable to generally determine if two given plans will produce the same
+   * Since its likely undecidable to generally determine if two given plans will produce the same
    * results, it is okay for this function to return false, even if the results are actually
    * the same.  Such behavior will not affect correctness, only the application of performance
    * enhancements like caching.  However, it is not acceptable to return true if the results could
@@ -111,9 +111,8 @@ abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
    */
   def resolveChildren(
       nameParts: Seq[String],
-      resolver: Resolver,
-      throwErrors: Boolean = false): Option[NamedExpression] =
-    resolve(nameParts, children.flatMap(_.output), resolver, throwErrors)
+      resolver: Resolver): Option[NamedExpression] =
+    resolve(nameParts, children.flatMap(_.output), resolver)
 
   /**
    * Optionally resolves the given strings to a [[NamedExpression]] based on the output of this
@@ -122,9 +121,8 @@ abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
    */
   def resolve(
       nameParts: Seq[String],
-      resolver: Resolver,
-      throwErrors: Boolean = false): Option[NamedExpression] =
-    resolve(nameParts, output, resolver, throwErrors)
+      resolver: Resolver): Option[NamedExpression] =
+    resolve(nameParts, output, resolver)
 
   /**
    * Given an attribute name, split it to name parts by dot, but
@@ -134,7 +132,7 @@ abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
   def resolveQuoted(
       name: String,
       resolver: Resolver): Option[NamedExpression] = {
-    resolve(parseAttributeName(name), resolver, true)
+    resolve(parseAttributeName(name), output, resolver)
   }
 
   /**
@@ -219,8 +217,7 @@ abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
   protected def resolve(
       nameParts: Seq[String],
       input: Seq[Attribute],
-      resolver: Resolver,
-      throwErrors: Boolean): Option[NamedExpression] = {
+      resolver: Resolver): Option[NamedExpression] = {
 
     // A sequence of possible candidate matches.
     // Each candidate is a tuple. The first element is a resolved attribute, followed by a list
@@ -254,19 +251,15 @@ abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
 
       // One match, but we also need to extract the requested nested field.
       case Seq((a, nestedFields)) =>
-        try {
-          // The foldLeft adds GetFields for every remaining parts of the identifier,
-          // and aliases it with the last part of the identifier.
-          // For example, consider "a.b.c", where "a" is resolved to an existing attribute.
-          // Then this will add GetField("c", GetField("b", a)), and alias
-          // the final expression as "c".
-          val fieldExprs = nestedFields.foldLeft(a: Expression)((expr, fieldName) =>
-            ExtractValue(expr, Literal(fieldName), resolver))
-          val aliasName = nestedFields.last
-          Some(Alias(fieldExprs, aliasName)())
-        } catch {
-          case a: AnalysisException if !throwErrors => None
-        }
+        // The foldLeft adds ExtractValues for every remaining parts of the identifier,
+        // and aliases it with the last part of the identifier.
+        // For example, consider "a.b.c", where "a" is resolved to an existing attribute.
+        // Then this will add ExtractValue("c", ExtractValue("b", a)), and alias
+        // the final expression as "c".
+        val fieldExprs = nestedFields.foldLeft(a: Expression)((expr, fieldName) =>
+          ExtractValue(expr, Literal(fieldName), resolver))
+        val aliasName = nestedFields.last
+        Some(Alias(fieldExprs, aliasName)())
 
       // No matches.
       case Seq() =>

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

@@ -285,7 +285,7 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] {
    * @param rule the function use to transform this nodes children
    */
   def transformUp(rule: PartialFunction[BaseType, BaseType]): BaseType = {
-    val afterRuleOnChildren = transformChildrenUp(rule);
+    val afterRuleOnChildren = transformChildrenUp(rule)
     if (this fastEquals afterRuleOnChildren) {
       CurrentOrigin.withOrigin(origin) {
         rule.applyOrElse(this, identity[BaseType])

sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

@@ -1440,4 +1440,12 @@ class SQLQuerySuite extends QueryTest with BeforeAndAfterAll with SQLTestUtils {
       checkAnswer(sql("select i <=> b from t"), sql("select r2 from t"))
     }
   }
+
+  test("SPARK-7067: order by queries for complex ExtractValue chain") {
+    withTempTable("t") {
+      sqlContext.read.json(sqlContext.sparkContext.makeRDD(
+        """{"a": {"b": [{"c": 1}]}, "b": [{"d": 1}]}""" :: Nil)).registerTempTable("t")
+      checkAnswer(sql("SELECT a.b FROM t ORDER BY b[0].d"), Row(Seq(Row(1))))
+    }
+  }
 }