revert

Author: gengliangwang

docs/sql-ref-ansi-compliance.md

@@ -255,7 +255,6 @@ The behavior of some SQL functions can be different under ANSI mode (`spark.sql.
 The behavior of some SQL operators can be different under ANSI mode (`spark.sql.ansi.enabled=true`).
   - `array_col[index]`: This operator throws `ArrayIndexOutOfBoundsException` if using invalid indices.
   - `map_col[key]`: This operator throws `NoSuchElementException` if key does not exist in map.
-  - `GROUP BY`: aliases in a select list can not be used in GROUP BY clauses. Each column referenced in a GROUP BY clause shall unambiguously reference a column of the table resulting from the FROM clause.
 
 ### Useful Functions for ANSI Mode
 

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

@@ -1948,7 +1948,7 @@ class Analyzer(override val catalogManager: CatalogManager)
       // mayResolveAttrByAggregateExprs requires the TreePattern UNRESOLVED_ATTRIBUTE.
       _.containsAllPatterns(AGGREGATE, UNRESOLVED_ATTRIBUTE), ruleId) {
       case agg @ Aggregate(groups, aggs, child)
-          if allowGroupByAlias && child.resolved && aggs.forall(_.resolved) &&
+          if conf.groupByAliases && child.resolved && aggs.forall(_.resolved) &&
             groups.exists(!_.resolved) =>
         agg.copy(groupingExpressions = mayResolveAttrByAggregateExprs(groups, aggs, child))
     }

sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -240,17 +240,6 @@ object SQLConf {
     .intConf
     .createWithDefault(100)
 
-  val ANSI_ENABLED = buildConf("spark.sql.ansi.enabled")
-    .doc("When true, Spark SQL uses an ANSI compliant dialect instead of being Hive compliant. " +
-      "For example, Spark will throw an exception at runtime instead of returning null results " +
-      "when the inputs to a SQL operator/function are invalid." +
-      "For full details of this dialect, you can find them in the section \"ANSI Compliance\" of " +
-      "Spark's documentation. Some ANSI dialect features may be not from the ANSI SQL " +
-      "standard directly, but their behaviors align with ANSI SQL's style")
-    .version("3.0.0")
-    .booleanConf
-    .createWithDefault(false)
-
   val OPTIMIZER_EXCLUDED_RULES = buildConf("spark.sql.optimizer.excludedRules")
     .doc("Configures a list of rules to be disabled in the optimizer, in which the rules are " +
       "specified by their rule names and separated by comma. It is not guaranteed that all the " +
@@ -1221,9 +1210,8 @@ object SQLConf {
     .createWithDefault(true)
 
   val GROUP_BY_ALIASES = buildConf("spark.sql.groupByAliases")
-    .doc("This configuration is only effective when ANSI mode is disabled. When it is true and " +
-      s"${ANSI_ENABLED.key} is false, aliases in a select list can be used in group by clauses. " +
-      "Otherwise, an analysis exception is thrown in the case.")
+    .doc("When true, aliases in a select list can be used in group by clauses. When false, " +
+      "an analysis exception is thrown in the case.")
     .version("2.2.0")
     .booleanConf
     .createWithDefault(true)
@@ -2547,6 +2535,17 @@ object SQLConf {
       .checkValues(StoreAssignmentPolicy.values.map(_.toString))
       .createWithDefault(StoreAssignmentPolicy.ANSI.toString)
 
+  val ANSI_ENABLED = buildConf("spark.sql.ansi.enabled")
+    .doc("When true, Spark SQL uses an ANSI compliant dialect instead of being Hive compliant. " +
+      "For example, Spark will throw an exception at runtime instead of returning null results " +
+      "when the inputs to a SQL operator/function are invalid." +
+      "For full details of this dialect, you can find them in the section \"ANSI Compliance\" of " +
+      "Spark's documentation. Some ANSI dialect features may be not from the ANSI SQL " +
+      "standard directly, but their behaviors align with ANSI SQL's style")
+    .version("3.0.0")
+    .booleanConf
+    .createWithDefault(false)
+
   val SORT_BEFORE_REPARTITION =
     buildConf("spark.sql.execution.sortBeforeRepartition")
       .internal()