Fix

src/Columns/ColumnDynamic.h

@@ -286,11 +286,13 @@ public:
     void forEachSubcolumn(MutableColumnCallback callback) override
     {
         callback(variant_column);
+        variant_column_ptr = assert_cast<ColumnVariant *>(variant_column.get());
     }
 
     void forEachSubcolumnRecursively(RecursiveMutableColumnCallback callback) override
     {
         callback(*variant_column);
+        variant_column_ptr = assert_cast<ColumnVariant *>(variant_column.get());
         variant_column->forEachSubcolumnRecursively(callback);
     }
 
@@ -364,6 +366,9 @@ private:
     void updateVariantInfoAndExpandVariantColumn(const DataTypePtr & new_variant_type);
 
     WrappedPtr variant_column;
+    /// Store and use pointer to ColumnVariant to avoid virtual calls.
+    /// ColumnDynamic is widely used inside ColumnObject for each path and
+    /// with hundreds of paths these virtual calls are noticeable.
     ColumnVariant * variant_column_ptr;
     /// Store the type of current variant with some additional information.
     VariantInfo variant_info;

src/Columns/ColumnObject.cpp

@@ -955,8 +955,11 @@ void ColumnObject::forEachSubcolumn(DB::IColumn::MutableColumnCallback callback)
 {
     for (auto & [_, column] : typed_paths)
         callback(column);
-    for (auto & [_, column] : dynamic_paths)
+    for (auto & [path, column] : dynamic_paths)
+    {
         callback(column);
+        dynamic_paths_ptrs[path] = assert_cast<ColumnDynamic *>(column.get());
+    }
     callback(shared_data);
 }
 
@@ -967,10 +970,11 @@ void ColumnObject::forEachSubcolumnRecursively(DB::IColumn::RecursiveMutableColu
         callback(*column);
         column->forEachSubcolumnRecursively(callback);
     }
-    for (auto & [_, column] : dynamic_paths_ptrs)
+    for (auto & [path, column] : dynamic_paths)
     {
         callback(*column);
         column->forEachSubcolumnRecursively(callback);
+        dynamic_paths_ptrs[path] = assert_cast<ColumnDynamic *>(column.get());
     }
     callback(*shared_data);
     shared_data->forEachSubcolumnRecursively(callback);

src/Columns/ColumnObject.h

@@ -201,6 +201,8 @@ private:
     /// here are Dynamic columns. This set of paths can be extended
     /// during inerts into the column.
     std::unordered_map<String, WrappedPtr> dynamic_paths;
+    /// Store and use pointers to ColumnDynamic to avoid virtual calls.
+    /// With hundreds of dynamic paths these virtual calls are noticeable.
     std::unordered_map<String, ColumnDynamic *> dynamic_paths_ptrs;
     /// Shared storage for all other paths and values. It's filled
     /// when the number of dynamic paths reaches the limit.

utils/check-style/aspell-ignore/en/aspell-dict.txt

@@ -2117,6 +2117,7 @@ natively
 nats
 nestjs
 netloc
+newjson
 ngram
 ngramDistance
 ngramDistanceCaseInsensitive