diff --git a/include/sqlpp11/core/basic/column.h b/include/sqlpp11/core/basic/column.h
index 4e74fdba..ae6750d4 100644
--- a/include/sqlpp11/core/basic/column.h
+++ b/include/sqlpp11/core/basic/column.h
@@ -34,7 +34,7 @@
 #include <sqlpp11/core/default_value.h>
 #include <sqlpp11/core/type_traits.h>
 #include <sqlpp11/core/wrong.h>
-#include <sqlpp11/core/detail/type_set.h>
+#include <sqlpp11/core/detail/type_vector.h>
 
 namespace sqlpp
 {
@@ -104,13 +104,18 @@ namespace sqlpp
   {
   };
 
-  template<typename Table>
-    struct table_t;
+  template <typename Table>
+  struct table_t;
 
   template<typename Table, typename ColumnSpec>
   struct required_tables_of<column_t<Table, ColumnSpec>>
   {
-    using type = detail::type_set<table_t<Table>>;
+    using type = detail::type_vector<table_t<Table>>;
+  };
+
+  template <typename Table, typename ColumnSpec>
+  struct required_static_tables_of<column_t<Table, ColumnSpec>> : public required_tables_of<column_t<Table, ColumnSpec>>
+  {
   };
 
   template <typename Context, typename Table, typename ColumnSpec>
diff --git a/include/sqlpp11/core/basic/join.h b/include/sqlpp11/core/basic/join.h
index 3b132b52..9fdc5fa1 100644
--- a/include/sqlpp11/core/basic/join.h
+++ b/include/sqlpp11/core/basic/join.h
@@ -67,18 +67,36 @@ namespace sqlpp
 #warning: We should mix dynamic and optional into the provided_tables_of (instead of having separate traits for each).
 #warning: it might be great to search for missing tables and return something like `missing_table_for<column_t<SomeSpec>>`.
 
+  template<typename T>
+    struct is_dynamic : public std::false_type {};
+  template<typename T>
+    struct is_dynamic<dynamic_t<T>> : public std::true_type {};
+
+  template <typename Lhs, typename JoinType, typename Rhs, typename Condition>
+  struct provided_tables_of<join_t<Lhs, JoinType, Rhs, Condition>>
+  {
+    using type = detail::type_vector_cat_t<provided_tables_of_t<Lhs>, provided_tables_of_t<Rhs>>;
+  };
+
+  template <typename Lhs, typename JoinType, typename Rhs, typename Condition>
+  struct provided_static_tables_of<join_t<Lhs, JoinType, Rhs, Condition>>
+  {
+    using type = typename std::conditional<
+        is_dynamic<Rhs>::value,
+        provided_static_tables_of<Lhs>,
+        detail::type_vector_cat_t<provided_static_tables_of<Lhs>, provided_static_tables_of<Rhs>>>::type;
+  };
+
   template <typename Lhs, typename JoinType, typename Rhs, typename Condition>
   struct provided_optional_tables_of<join_t<Lhs, JoinType, Rhs, Condition>>
   {
-    using type = typename std::conditional<
-        std::is_same<JoinType, left_outer_join_t>::value,
-        sqlpp::detail::type_set<Rhs>,
-        typename std::conditional<
-            std::is_same<JoinType, right_outer_join_t>::value,
-            sqlpp::detail::type_set<Lhs>,
-            typename std::conditional<std::is_same<JoinType, full_outer_join_t>::value,
-                                      detail::make_joined_set_t<provided_tables_of_t<Lhs>, provided_tables_of_t<Rhs>>,
-                                      detail::type_set<>>::type>::type>::type;
+    using type = detail::type_vector_cat_t<
+        typename std::conditional<detail::type_vector<right_outer_join_t, full_outer_join_t>::contains<JoinType>(),
+                                  provided_tables_of_t<Lhs>,
+                                  detail::type_vector<>>::type,
+        typename std::conditional<detail::type_vector<left_outer_join_t, full_outer_join_t>::contains<JoinType>(),
+                                  provided_tables_of_t<Rhs>,
+                                  detail::type_vector<>>::type>;
   };
 
   template <typename Lhs, typename JoinType, typename Rhs, typename Condition>
@@ -124,8 +142,36 @@ namespace sqlpp
 
 #warning: Verify that the Expr does not require tables other than Lhs, Rhs
   //and detail::make_joined_set_t<provided_tables_of_t<Lhs>, provided_tables_of_t<Rhs>>::is_superset_of<required_tables_of_t<Expr>::value
+  template <typename Expr, typename StaticTableTypeVector, typename AllTableTypeVector>
+  struct are_table_requirements_satisfied
+      : std::integral_constant<bool,
+                               StaticTableTypeVector::contains_all(required_static_tables_of_t<Expr>{}) and
+                                   AllTableTypeVector::contains_all(required_tables_of_t<Expr>{})>
+  {
+  };
+
   template <typename Lhs, typename Rhs, typename Expr>
-    using check_on_args = sqlpp::enable_if_t<sqlpp::is_boolean<Expr>::value>;
+  struct are_join_table_requirements_satisfied
+      : public std::integral_constant<
+            bool,
+            is_dynamic<Rhs>::value ?
+                                   // In case of a dynamic join, we can use all tables in the ON expr.
+                are_table_requirements_satisfied<
+                    Expr,
+                    provided_tables_of_t<join_t<Lhs, cross_join_t, Rhs, unconditional_t>>,
+                    provided_tables_of_t<join_t<Lhs, cross_join_t, Rhs, unconditional_t>>>::value
+                                   :
+                                   // In case of a static join, we can use static tables in the static part of the ON
+                                   // expression and dynamic tables in any potential dynamic part of the expression.
+                are_table_requirements_satisfied<
+                    Expr,
+                    provided_static_tables_of_t<join_t<Lhs, cross_join_t, Rhs, unconditional_t>>,
+                    provided_tables_of_t<join_t<Lhs, cross_join_t, Rhs, unconditional_t>>>::value>
+  {
+  };
+
+  template <typename Lhs, typename Rhs, typename Expr>
+    using check_on_args = sqlpp::enable_if_t<sqlpp::is_boolean<Expr>::value and are_join_table_requirements_satisfied<Lhs, Rhs, Expr>::value>;
 
   template <typename Lhs, typename JoinType, typename Rhs>
   struct pre_join_t
@@ -133,7 +179,7 @@ namespace sqlpp
     template <typename Expr, typename = check_on_args<Lhs, Rhs, Expr>>
     auto on(Expr expr) const -> join_t<Lhs, JoinType, Rhs, Expr>
     {
-      return {_lhs, _rhs, std::move(expr)};
+     return {_lhs, _rhs, std::move(expr)};
     }
 
     Lhs _lhs;
diff --git a/include/sqlpp11/core/basic/table.h b/include/sqlpp11/core/basic/table.h
index e4fb1179..19128f10 100644
--- a/include/sqlpp11/core/basic/table.h
+++ b/include/sqlpp11/core/basic/table.h
@@ -69,6 +69,16 @@ namespace sqlpp
     using type = sqlpp::detail::type_set<table_t<TableSpec>>;
   };
 
+  template <typename TableSpec>
+  struct provided_static_tables_of<table_t<TableSpec>> : public provided_tables_of<table_t<TableSpec>>
+  {
+  };
+
+  template <typename TableSpec>
+  struct provided_optional_tables_of<table_t<TableSpec>> : public provided_tables_of<table_t<TableSpec>>
+  {
+  };
+
   template <typename Context, typename TableSpec>
   auto to_sql_string(Context& context, const table_t<TableSpec>& /*unused*/) -> std::string
   {
diff --git a/include/sqlpp11/core/clause/where.h b/include/sqlpp11/core/clause/where.h
index e4715d69..7b066b1f 100644
--- a/include/sqlpp11/core/clause/where.h
+++ b/include/sqlpp11/core/clause/where.h
@@ -159,7 +159,7 @@ namespace sqlpp
       using _new_statement_t = new_statement_t<Check, Policies, no_where_t, T>;
 
       using _consistency_check =
-          typename std::conditional<WhereRequired and (Policies::_all_provided_tables::size::value > 0),
+          typename std::conditional<WhereRequired and (Policies::_all_provided_tables::size() > 0),
                                     assert_where_or_unconditionally_called_t,
                                     consistent_t>::type;
 
diff --git a/include/sqlpp11/core/detail/type_vector.h b/include/sqlpp11/core/detail/type_vector.h
index 9bf4d633..c727fafa 100644
--- a/include/sqlpp11/core/detail/type_vector.h
+++ b/include/sqlpp11/core/detail/type_vector.h
@@ -36,16 +36,26 @@ namespace sqlpp
     template <typename... T>
     struct type_vector
     {
-      template<typename X>
-      using contains = std::integral_constant<bool, ::sqlpp::logic::any<std::is_same<T, X>::value...>::value>;
+      template <typename X>
+      static constexpr bool contains()
+      {
+        return ::sqlpp::logic::any<std::is_same<T, X>::value...>::value;
+      }
 
-      template <template <typename> class Transform>
-      using transform = type_vector<typename Transform<T>::type...>;
+      template <typename... X>
+      static constexpr bool contains_all(type_vector<X...>)
+      {
+        return ::sqlpp::logic::all<contains<X>()...>::value;
+      }
 
-      static constexpr bool size = sizeof...(T);
+      static constexpr size_t size()
+      {
+        return sizeof...(T);
+      }
 
-      static constexpr bool empty() {
-        return size == 0;
+      static constexpr bool empty()
+      {
+        return size() == 0;
       }
     };
 
@@ -82,5 +92,17 @@ namespace sqlpp
     template <typename... T>
     using type_vector_cat_t = typename type_vector_cat_impl<T...>::type;
 
+    template <typename TypeVector, template <typename> class Transform>
+    struct transform;
+
+    template <template <typename> class Transform, typename... T>
+    struct transform<type_vector<T...>, Transform>
+    {
+      using type = type_vector<typename Transform<T>::type...>;
+    };
+
+    template <typename TypeVector, template <typename> class Transform>
+    using transform_t = typename transform<TypeVector, Transform>::type;
+
   }  // namespace detail
 }  // namespace sqlpp
diff --git a/include/sqlpp11/core/query/statement.h b/include/sqlpp11/core/query/statement.h
index 52cbd403..d52373be 100644
--- a/include/sqlpp11/core/query/statement.h
+++ b/include/sqlpp11/core/query/statement.h
@@ -78,12 +78,15 @@ namespace sqlpp
       using _all_required_ctes = detail::make_joined_set_t<required_ctes_of<Policies>...>;
       using _all_provided_ctes = detail::make_joined_set_t<provided_ctes_of<Policies>...>;
       using _all_required_tables = detail::make_joined_set_t<required_tables_of_t<Policies>...>;
-      using _all_provided_tables = detail::make_joined_set_t<provided_tables_of_t<Policies>...>;
-      using _all_provided_outer_tables = detail::make_joined_set_t<provided_optional_tables_of_t<Policies>...>;
+      using _all_provided_tables = detail::type_vector_cat_t<provided_tables_of_t<Policies>...>;
+      //using _all_provided_outer_tables = detail::make_joined_set_t<provided_optional_tables_of_t<Policies>...>;
       using _all_provided_aggregates = detail::make_joined_set_t<provided_aggregates_of<Policies>...>;
 
+#warning reactivate
+      /*
       template <typename Expression>
       using _no_unknown_tables = detail::is_subset_of<required_tables_of_t<Expression>, _all_provided_tables>;
+      */
 
       // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2086629
       //	  template <typename... Expressions>
@@ -109,7 +112,7 @@ namespace sqlpp
       using any_t = logic::any<Predicate<Policies>::value...>;
 
       // The tables not covered by the from.
-      using _required_tables = detail::make_difference_set_t<_all_required_tables, _all_provided_tables>;
+      //using _required_tables = detail::make_difference_set_t<_all_required_tables, _all_provided_tables>;
 
       // The common table expressions not covered by the with.
       using _required_ctes = detail::make_difference_set_t<_all_required_ctes, _all_provided_ctes>;
@@ -125,7 +128,8 @@ namespace sqlpp
       //   - the select is complete (leaks no table requirements or cte requirements)
       static constexpr bool _can_be_used_as_table()
       {
-        return has_result_row_t<_statement_t>::value and _required_tables::size::value == 0 and
+#warning: reactivate
+        return has_result_row_t<_statement_t>::value and /*_required_tables::size::value == 0 and*/
                _required_ctes::size::value == 0;
       }
 
@@ -147,8 +151,9 @@ namespace sqlpp
 
       using _cte_check =
           typename std::conditional<_required_ctes::size::value == 0, consistent_t, assert_no_unknown_ctes_t>::type;
-      using _table_check =
-          typename std::conditional<_required_tables::size::value == 0, consistent_t, assert_no_unknown_tables_t>::type;
+#warning: reactivate
+      using _table_check = std::true_type;
+          //typename std::conditional<_required_tables::size::value == 0, consistent_t, assert_no_unknown_tables_t>::type;
       using _parameter_check = typename std::
           conditional<_parameters::empty(), consistent_t, assert_no_parameters_t>::type;
     };
@@ -206,7 +211,7 @@ namespace sqlpp
                       >;
     using _name_tag_of = name_tag_of<_result_type_provider>;
     using _nodes = detail::type_vector<_policies_t>;
-    using _used_outer_tables = typename _policies_t::_all_provided_outer_tables;
+    //using _used_outer_tables = typename _policies_t::_all_provided_outer_tables;
 
     // Constructors
     statement_t() = default;
diff --git a/include/sqlpp11/core/type_traits/tables_of.h b/include/sqlpp11/core/type_traits/tables_of.h
index 0ef8f40c..1ac73a30 100644
--- a/include/sqlpp11/core/type_traits/tables_of.h
+++ b/include/sqlpp11/core/type_traits/tables_of.h
@@ -45,12 +45,27 @@ namespace sqlpp
   template<typename... T>
   struct required_tables_of<detail::type_vector<T...>>
   {
-    using type = detail::make_joined_set_t<typename required_tables_of<T>::type...>;
+    using type = detail::type_vector_cat_t<typename required_tables_of<T>::type...>;
   };
 
   template<typename T>
     using required_tables_of_t = typename required_tables_of<T>::type;
 
+  template<typename T>
+  struct required_static_tables_of
+  {
+    using type = typename required_static_tables_of<nodes_of_t<T>>::type;
+  };
+
+  template<typename... T>
+  struct required_static_tables_of<detail::type_vector<T...>>
+  {
+    using type = detail::type_vector_cat_t<typename required_static_tables_of<T>::type...>;
+  };
+
+  template<typename T>
+    using required_static_tables_of_t = typename required_static_tables_of<T>::type;
+
 #warning: need type tests...
   //static_assert(required_tables_of_t<int>::size::value == 0, "");
 
@@ -66,16 +81,27 @@ namespace sqlpp
   template <typename... T>
   struct provided_tables_of<detail::type_vector<T...>>
   {
-    using type = detail::make_joined_set_t<typename provided_tables_of<T>::type...>;
+    using type = detail::type_vector_cat_t<typename provided_tables_of<T>::type...>;
   };
 
   template <typename T>
   using provided_tables_of_t = typename provided_tables_of<T>::type;
 
-  static_assert(provided_tables_of_t<int>::size::value == 0, "");
+  template <typename T>
+  struct provided_static_tables_of
+  {
+    using type = typename provided_static_tables_of<nodes_of_t<T>>::type;
+  };
+
+  template <typename... T>
+  struct provided_static_tables_of<detail::type_vector<T...>>
+  {
+    using type = detail::type_vector_cat_t<typename provided_static_tables_of<T>::type...>;
+  };
+
+  template <typename T>
+  using provided_static_tables_of_t = typename provided_static_tables_of<T>::type;
 
-  // provided_optional_tables_of is similar to provided_tables_of but only references the tables that have optional
-  // rows in outer joins (e.g. the right hand side table in a LEFT OUTER JOIN).
   template <typename T>
   struct provided_optional_tables_of
   {
@@ -85,11 +111,13 @@ namespace sqlpp
   template <typename... T>
   struct provided_optional_tables_of<detail::type_vector<T...>>
   {
-    using type = detail::make_joined_set_t<typename provided_optional_tables_of<T>::type...>;
+    using type = detail::type_vector_cat_t<typename provided_optional_tables_of<T>::type...>;
   };
 
   template <typename T>
   using provided_optional_tables_of_t = typename provided_optional_tables_of<T>::type;
 
+  static_assert(provided_tables_of_t<int>::empty(), "");
+
 }  // namespace sqlpp