Update Optimizer.scala

Author: pzzs

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala

@@ -36,20 +36,21 @@ object DefaultOptimizer extends Optimizer {
     // SubQueries are only needed for analysis and can be removed before execution.
     Batch("Remove SubQueries", FixedPoint(100),
       EliminateSubQueries) ::
-    Batch("Operator Optimizations", FixedPoint(100),
+    Batch("Operator Reordering", FixedPoint(100),
       UnionPushdown,
       CombineFilters,
       PushPredicateThroughProject,
+      PushPredicateThroughJoin,
       PushPredicateThroughGenerate,
       ColumnPruning,
       ProjectCollapsing,
-      CombineLimits,
+      CombineLimits) ::
+    Batch("ConstantFolding", FixedPoint(100),
       NullPropagation,
       OptimizeIn,
       ConstantFolding,
       LikeSimplification,
       BooleanSimplification,
-      PushPredicateThroughJoin,
       SimplifyFilters,
       SimplifyCasts,
       SimplifyCaseConversionExpressions) ::