cloud-fan commented on code in PR #39508: URL: https://github.com/apache/spark/pull/39508#discussion_r1066896772
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveReferencesInAggregate.scala: ########## @@ -0,0 +1,183 @@ +/* + * 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.analysis + +import org.apache.spark.sql.catalyst.SQLConfHelper +import org.apache.spark.sql.catalyst.expressions.{Alias, Attribute, Expression, GetStructField, NamedExpression} +import org.apache.spark.sql.catalyst.expressions.aggregate.AggregateExpression +import org.apache.spark.sql.catalyst.plans.logical.{Aggregate, AppendColumns, LogicalPlan} +import org.apache.spark.sql.catalyst.trees.TreePattern.UNRESOLVED_ATTRIBUTE + +/** + * A virtual rule to resolve [[UnresolvedAttribute]] in [[Aggregate]]. It's only used by the real + * rule `ResolveReferences`. The column resolution order for [[Aggregate]] is: + * 1. Resolves the column to [[AttributeReference]] with the output of the child plan. This + * includes metadata columns as well. + * 2. Resolves the column to a literal function which is allowed to be invoked without braces, e.g. + * `SELECT col, current_date FROM t`. + * 3. Resolves the column to [[LateralColumnAliasReference]] if it references the alias defined + * previously in the SELECT list. The rule `ResolveLateralColumnAliasReference` will further + * resolve [[LateralColumnAliasReference]] and rewrite the plan. This is to support SQL pattern + * like `SELECT col1 + 1 AS x, x + 1 AS y, y + 1 AS z FROM t`. + * 4. If the group by expressions contain an unresolved column whose name matches an alias in the + * SELECT list, resolves that unresolved column to the alias if the alias is resolved. This is to + * support SQL pattern like `SELECT a + b AS c, max(col) FROM t GROUP BY c`. + * 5. If the group by expressions only have one single unresolved column named ALL, expanded it to + * include all non-aggregate columns in the SELECT list. This is to support SQL pattern like + * `SELECT col1, col2, agg_expr(...) FROM t GROUP BY ALL`. + * 6. Resolves the column to outer references with the outer plan if we are resolving subquery + * expressions. + */ +object ResolveReferencesInAggregate extends SQLConfHelper with ColumnResolutionHelper { + def apply(a: Aggregate): Aggregate = { + val planForResolve = a.child match { + // SPARK-25942: Resolves aggregate expressions with `AppendColumns`'s children, instead of + // `AppendColumns`, because `AppendColumns`'s serializer might produce conflict attribute + // names leading to ambiguous references exception. + case appendColumns: AppendColumns => appendColumns + case _ => a + } + + val resolvedAggExprsNoOuter = a.aggregateExpressions + .map(resolveExpressionByPlanChildren(_, planForResolve, allowOuter = false) + .asInstanceOf[NamedExpression]) + + val resolvedGroupingExprs = a.groupingExpressions + .map(resolveExpressionByPlanChildren(_, planForResolve, allowOuter = false)) + // SPARK-31670: Resolve Struct field in groupByExpressions and aggregateExpressions + // with CUBE/ROLLUP will be wrapped with alias like Alias(GetStructField, name) with + // different ExprId. This cause aggregateExpressions can't be replaced by expanded + // groupByExpressions in `ResolveGroupingAnalytics.constructAggregateExprs()`, we trim + // unnecessary alias of GetStructField here. + .map(trimTopLevelGetStructFieldAlias) + + if (resolvedAggExprsNoOuter.forall(_.resolved)) { + val finalGroupExprs = resolveGroupByAll( + resolvedAggExprsNoOuter, + resolveGroupByAlias(resolvedAggExprsNoOuter, resolvedGroupingExprs) + ).map(resolveOuterRef) Review Comment: This is the actual change. Now we resolve group by alias and group by all before resolving outer references. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
