Review comments

Author: szehon-ho

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala

@@ -710,6 +710,7 @@ case class HashShuffleSpec(
 
 /**
  * [[ShuffleSpec]] created by [[KeyGroupedPartitioning]].
+ *
  * @param partitioning key grouped partitioning
  * @param distribution distribution
  * @param joinKeyPosition position of join keys among cluster keys.

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

@@ -1533,10 +1533,9 @@ object SQLConf {
   val V2_BUCKETING_ALLOW_JOIN_KEYS_SUBSET_OF_PARTITION_KEYS =
     buildConf("spark.sql.sources.v2.bucketing.allowJoinKeysSubsetOfPartitionKeys.enabled")
       .doc("Whether to allow storage-partition join in the case where join keys are" +
-        "a subset of the partition keys of the source tables.  At planning time, " +
+        "a subset of the partition keys of the source tables. At planning time, " +
         "Spark will group the partitions by only those keys that are in the join keys." +
-        "This is currently enabled only if spark.sql.requireAllClusterKeysForDistribution " +
-        "is false."
+        s"This is currently enabled only if $REQUIRE_ALL_CLUSTER_KEYS_FOR_DISTRIBUTION is false." +
       )
       .version("4.0.0")
       .booleanConf