Fix build.

src/Interpreters/addMissingDefaults.h

@@ -2,6 +2,7 @@
 
 #include <unordered_map>
 #include <string>
+#include <memory>
 
 
 namespace DB

src/Processors/QueryPlan/Optimizations/filterPushDown.cpp

@@ -0,0 +1,22 @@
+#include <Processors/QueryPlan/Optimizations/Optimizations.h>
+#include <Processors/QueryPlan/FilterStep.h>
+
+namespace DB::QueryPlanOptimizations
+{
+
+size_t tryPushDownLimit(QueryPlan::Node * node, QueryPlan::Nodes &)
+{
+    auto * filter_step = typeid_cast<FilterStep *>(node->step.get());
+    if (!filter_step)
+        return 0;
+
+    QueryPlan::Node * child_node = node->children.front();
+    auto & child = child_node->step;
+
+    if (const auto * adding_const_column = typeid_cast<const AddingConstColumnStep *>(child.get()))
+    {
+
+    }
+}
+
+}