Try to remove some code.

dbms/src/DataStreams/ConvertingBlockInputStream.cpp

@@ -1,11 +1,11 @@
 #include <DataStreams/ConvertingBlockInputStream.h>
-#include <Interpreters/addMissingDefaults.h>
 #include <Interpreters/castColumn.h>
 #include <Columns/ColumnConst.h>
 #include <Common/assert_cast.h>
 #include <Common/quoteString.h>
 #include <Parsers/IAST.h>
 
+
 namespace DB
 {
 
@@ -35,9 +35,8 @@ ConvertingBlockInputStream::ConvertingBlockInputStream(
     const Context & context_,
     const BlockInputStreamPtr & input,
     const Block & result_header,
-    MatchColumnsMode mode,
-    const ColumnDefaults & column_defaults_)
-    : context(context_), header(result_header), column_defaults(column_defaults_), conversion(header.columns())
+    MatchColumnsMode mode)
+    : context(context_), header(result_header), conversion(header.columns())
 {
     children.emplace_back(input);
 
@@ -66,18 +65,8 @@ ConvertingBlockInputStream::ConvertingBlockInputStream(
                     throw Exception("Cannot find column " + backQuote(res_elem.name) + " in source stream",
                         ErrorCodes::THERE_IS_NO_COLUMN);
                 break;
-
-            case MatchColumnsMode::NameOrDefault:
-                if (input_header.has(res_elem.name))
-                    conversion[result_col_num] = input_header.getPositionByName(res_elem.name);
-                else
-                    conversion[result_col_num] = USE_DEFAULT;
-                break;
         }
 
-        if (conversion[result_col_num] == USE_DEFAULT)
-            continue;
-
         const auto & src_elem = input_header.getByPosition(conversion[result_col_num]);
 
         /// Check constants.
@@ -104,7 +93,6 @@ ConvertingBlockInputStream::ConvertingBlockInputStream(
 Block ConvertingBlockInputStream::readImpl()
 {
     Block src = children.back()->read();
-    std::set<size_t> default_columns;
 
     if (!src)
         return src;
@@ -112,15 +100,8 @@ Block ConvertingBlockInputStream::readImpl()
     Block res = header.cloneEmpty();
     for (size_t res_pos = 0, size = conversion.size(); res_pos < size; ++res_pos)
     {
-        auto & res_elem = res.getByPosition(res_pos);
-
-        if (conversion[res_pos] == USE_DEFAULT)
-        {
-            default_columns.insert(res_pos);
-            continue;
-        }
-
         const auto & src_elem = src.getByPosition(conversion[res_pos]);
+        auto & res_elem = res.getByPosition(res_pos);
 
         ColumnPtr converted = castColumnWithDiagnostic(src_elem, res_elem, context);
 
@@ -129,16 +110,7 @@ Block ConvertingBlockInputStream::readImpl()
 
         res_elem.column = std::move(converted);
     }
-
-    // replace missing columns with default value or expression if any
-    if (!default_columns.empty())
-    {
-        res.erase(default_columns);
-        res = addMissingDefaults(res, header.getNamesAndTypesList(), column_defaults, context);
-    }
-
     return res;
 }
 
 }
-

dbms/src/DataStreams/ConvertingBlockInputStream.h

@@ -2,7 +2,6 @@
 
 #include <unordered_map>
 #include <DataStreams/IBlockInputStream.h>
-#include <Storages/ColumnDefault.h>
 
 
 namespace DB
@@ -29,17 +28,14 @@ public:
         /// Require same number of columns in source and result. Match columns by corresponding positions, regardless to names.
         Position,
         /// Find columns in source by their names. Allow excessive columns in source.
-        Name,
-        /// Find columns in source by their names if present else use the default. Allow excessive columns in source.
-        NameOrDefault
+        Name
     };
 
     ConvertingBlockInputStream(
         const Context & context,
         const BlockInputStreamPtr & input,
         const Block & result_header,
-        MatchColumnsMode mode,
-        const ColumnDefaults & column_defaults = {});
+        MatchColumnsMode mode);
 
     String getName() const override { return "Converting"; }
     Block getHeader() const override { return header; }
@@ -49,12 +45,9 @@ private:
 
     const Context & context;
     Block header;
-    /// Only used in NameOrDefault mode
-    const ColumnDefaults column_defaults;
 
     /// How to construct result block. Position in source block, where to get each column.
     using Conversion = std::vector<size_t>;
-    const size_t USE_DEFAULT = static_cast<size_t>(-1);
     Conversion conversion;
 };
 

dbms/src/DataStreams/PushingToViewsBlockOutputStream.cpp

@@ -13,6 +13,7 @@
 #include <Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h>
 #include <Storages/StorageValues.h>
 #include <Storages/LiveView/StorageLiveView.h>
+#include "AddingMissedBlockInputStream.h"
 
 namespace DB
 {
@@ -233,13 +234,14 @@ void PushingToViewsBlockOutputStream::process(const Block & block, size_t view_n
 
             auto view_table = context.getTable(view.table_id);
 
+            in = std::make_shared<ConvertingBlockInputStream>(context, in, view.out->getHeader(), ConvertingBlockInputStream::MatchColumnsMode::Name);
+
+            /// Add defaults to inner table in case it was altered after creation.
             if (auto * materialized_view = dynamic_cast<const StorageMaterializedView *>(view_table.get()))
             {
                 StoragePtr inner_table = materialized_view->getTargetTable();
-                in = std::make_shared<ConvertingBlockInputStream>(context, in, view.out->getHeader(), ConvertingBlockInputStream::MatchColumnsMode::NameOrDefault, inner_table->getColumns().getDefaults());
+                in = std::make_shared<AddingMissedBlockInputStream>(in, view.out->getHeader(), inner_table->getColumns().getDefaults(), context);
             }
-            else
-                in = std::make_shared<ConvertingBlockInputStream>(context, in, view.out->getHeader(), ConvertingBlockInputStream::MatchColumnsMode::Name);
         }
         else
             in = std::make_shared<OneBlockInputStream>(block);