EXPLAIN PLAN sortmode options

+ ActionsDAG fixes

src/Interpreters/ActionsDAG.cpp

@@ -1932,7 +1932,6 @@ bool ActionsDAG::isSortingPreserved(const SortDescription & sort_description) co
         const Field field{};
         std::unordered_set<const Node *> visited_nodes;
 
-        bool column_found = false;
         for (const auto & head : nodes)
         {
             const auto * root = &head;
@@ -1953,8 +1952,6 @@ bool ActionsDAG::isSortingPreserved(const SortDescription & sort_description) co
                 /// if found column
                 if (node == column)
                 {
-                    column_found = true;
-
                     backtrace.pop(); /// pop column itself
 
                     /// walk back to root and check functions
@@ -1994,16 +1991,25 @@ bool ActionsDAG::isSortingPreserved(const SortDescription & sort_description) co
             }
         }
 
-        return column_found;
+        return true;
     };
 
     for (const auto & column_sort_desc : sort_description)
     {
-        const auto * node = tryFindInIndex(column_sort_desc.column_name);
-        if (node && node->type == ActionsDAG::ActionType::INPUT)
+        for (const auto * node : inputs)
         {
-            if (!node_preserve_sorting(node))
+            if (!node)
+                continue;
+
+            if (node->result_name == column_sort_desc.column_name || (node->column && isColumnConst(*node->column)))
+            {
+                if (!node_preserve_sorting(node))
+                    return false;
+            }
+            else
+            {
                 return false;
+            }
         }
     }
     return true;

src/Interpreters/InterpreterExplainQuery.cpp

@@ -174,7 +174,8 @@ struct QueryPlanSettings
             {"actions", query_plan_options.actions},
             {"indexes", query_plan_options.indexes},
             {"optimize", optimize},
-            {"json", json}
+            {"json", json},
+            {"sortmode", query_plan_options.sort_mode},
     };
 };
 

src/Processors/QueryPlan/QueryPlan.cpp

@@ -327,7 +327,11 @@ static void explainStep(
         }
         settings.out.write('\n');
 
-        if (step.hasOutputStream() && step.getOutputStream().header)
+    }
+
+    if (options.sort_mode)
+    {
+        if (step.hasOutputStream())
         {
             settings.out << prefix << "Sort Mode: " << step.getOutputStream().sort_mode;
             if (step.getOutputStream().sort_mode != DataStream::SortMode::None)

src/Processors/QueryPlan/QueryPlan.h

@@ -71,6 +71,8 @@ public:
         bool actions = false;
         /// Add information about indexes actions.
         bool indexes = false;
+        /// Add information about sort mode
+        bool sort_mode = false;
     };
 
     struct ExplainPipelineOptions