Address all comments

Author: c21

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

@@ -1705,20 +1705,20 @@ object SQLConf {
       .doc("Enable two-level aggregate hash map. When enabled, records will first be " +
         "inserted/looked-up at a 1st-level, small, fast map, and then fallback to a " +
         "2nd-level, larger, slower map when 1st level is full or keys cannot be found. " +
-        "When disabled, records go directly to the 2nd level. Enable for partial aggregate only.")
+        "When disabled, records go directly to the 2nd level.")
       .version("2.3.0")
       .booleanConf
       .createWithDefault(true)
 
-  val ENABLE_TWOLEVEL_FINAL_AGG_MAP =
-    buildConf("spark.sql.codegen.aggregate.final.map.twolevel.enabled")
+  val ENABLE_TWOLEVEL_AGG_MAP_PARTIAL_ONLY =
+    buildConf("spark.sql.codegen.aggregate.map.twolevel.partialOnly")
       .internal()
-      .doc("Enable two-level aggregate hash map for final aggregate as well. Disable by default " +
+      .doc("Enable two-level aggregate hash map for partial aggregate only, " +
         "because final aggregate might get more distinct keys compared to partial aggregate. " +
         "Overhead of looking up 1st-level map might dominate when having a lot of distinct keys.")
-      .version("3.2.0")
+      .version("3.2.1")
       .booleanConf
-      .createWithDefault(false)
+      .createWithDefault(true)
 
   val ENABLE_VECTORIZED_HASH_MAP =
     buildConf("spark.sql.codegen.aggregate.map.vectorized.enable")
@@ -3875,7 +3875,7 @@ class SQLConf extends Serializable with Logging {
 
   def enableTwoLevelAggMap: Boolean = getConf(ENABLE_TWOLEVEL_AGG_MAP)
 
-  def enableTwoLevelFinalAggMap: Boolean = getConf(ENABLE_TWOLEVEL_FINAL_AGG_MAP)
+  def enableTwoLevelAggMapPartialOnly: Boolean = getConf(ENABLE_TWOLEVEL_AGG_MAP_PARTIAL_ONLY)
 
   def enableVectorizedHashMap: Boolean = getConf(ENABLE_VECTORIZED_HASH_MAP)
 

sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/HashAggregateExec.scala

@@ -671,7 +671,7 @@ case class HashAggregateExec(
       if (modes.forall(mode => mode == Partial || mode == PartialMerge)) {
         true
       } else {
-        conf.enableTwoLevelFinalAggMap
+        !conf.enableTwoLevelAggMapPartialOnly
       }
 
     isSupported && isNotByteArrayDecimalType && isEnabledForAggModes