diff --git a/tpl/macro.twig b/tpl/macro.twig
index d4eab1c..34a5da4 100644
--- a/tpl/macro.twig
+++ b/tpl/macro.twig
@@ -18,6 +18,10 @@
 {% endmacro %}
 
 {% macro decl_struct(o, extra = '') %}
+
+{% set pkey_fields = token(o, 'table_pkey')|split(',') %}
+{% set pkey = o.fields|filter(f => f.name in pkey_fields ) %}
+
   {%- if o.parent and has_token(o, 'POD') -%}
   {{Error("@POD structs can't have a parent: " ~ o.name)}}
   {%- endif -%}
@@ -81,10 +85,24 @@ public {{_self.struct_type(o)}} {{o.name}} {{_self.base_struct_class(o)}}
   {{_self.bitmask_helpers(o)}}
 {%- endif -%}
   
-{%- if has_token(o, 'id') ~%}
-  public ulong getPrimaryId() 
+{%- if has_token(o, 'table') ~%}
+  public static bool operator <({{o.name}} o1, {{o.name}} o2)
   {
-    return (ulong){{token(o, 'id')}};
+    return {{o.name}}Comparer.self.Compare(o1, o2) < 0;
+  }
+
+  public static bool operator >({{o.name}} o1, {{o.name}} o2)
+  {
+    return {{o.name}}Comparer.self.Compare(o1, o2) > 0;
+  }
+
+  public {{o.name}}Id MakeId()
+  {
+    return new {{o.name}}Id{
+      {% for f in pkey %}
+      {{f.name}} = {{f.name}},
+      {% endfor %}
+    };
   }
 {%- endif -%}
 
@@ -97,6 +115,27 @@ public {{_self.struct_type(o)}} {{o.name}} {{_self.base_struct_class(o)}}
   {{extra}}
 }
 
+{%- if has_token(o, 'table') ~%}
+public class {{o.name}}Comparer : IComparer<{{o.name}}>
+{
+  public readonly static {{o.name}}Comparer self = new {{o.name}}Comparer();
+
+  public int Compare({{o.name}} o1, {{o.name}} o2)
+  {
+    int result;
+
+    {% for f in pkey %}
+      {% if not loop.first %}
+      if(result == 0)
+      {% endif %}
+      result = o1.{{f.name}}.CompareTo(o2.{{f.name}});
+    {% endfor %}
+
+    return result;
+  }
+}
+{%- endif ~%}
+
 {% endmacro %}
 
 {%- macro decl_struct_fields(o) -%}
@@ -314,10 +353,12 @@ public class {{o.name}} : IRpc
 
 {%- macro diffable_support(o) -%}
 
-    public bool GetDiff({{o.name}} old, {{o.name}} diff = null, List<DataClassIds> removed = null)
+    public bool GetDiff({{o.name}} old, {{o.name}} diff = null, {{o.name}}RemovedIds removed = null)
     {
       if(diff != null) 
         diff.reset();
+      if(removed != null)
+        removed.reset();
       bool no_changes = true;
 
     {% set field_idx = -1 %}
@@ -336,52 +377,22 @@ public class {{o.name}} : IRpc
     {{_self.diff_methods_for(u)}}
     {% endfor %}
 
-    static public List<ulong> GetClassRemovedIds(List<DataClassIds> removed_ids, uint class_id) 
-    {
-      if(removed_ids == null)
-        return null;
-      DataClassIds res;
-      if(!FindClassRemovedIds(removed_ids, class_id, out res))
-      {
-        res = new DataClassIds();
-        res.class_id = class_id;
-        res.ids = new List<ulong>();
-        removed_ids.Add(res);
-      }
-      return res.ids;
-    }
-
-    static bool FindClassRemovedIds(List<DataClassIds> removed_ids, uint class_id, out DataClassIds res)
-    {
-      for(int i=0;i<removed_ids.Count;++i)
-      {
-        if(removed_ids[i].class_id == class_id)
-        {
-          res = removed_ids[i];
-          return true;
-        }
-      }
-      res = default(DataClassIds);
-      return false;
-    }
-
 {% endmacro %}
 
 {%- macro diff_methods_for(u) -%}
-
   static public bool DiffOne(ref {{u.name}} curr, {{u.name}} old)
   {
     return !{{_self.compare_func_name(u)}}(ref curr, old);
   }
 
-  static public bool DiffCollection(List<{{u.name}}> items, List<{{u.name}}> old_items, List<{{u.name}}> changed, List<DataClassIds> removed)
+  static public bool DiffCollection(List<{{u.name}}> items, List<{{u.name}}> old_items, List<{{u.name}}> changed, List<{{u.name}}Id> removed)
   {
     bool has_diff = false;
     if(changed != null)
       changed.Clear();
 
-    SortByPrimaryId(ref items);
-    SortByPrimaryId(ref old_items);
+    items.Sort({{u.name}}Comparer.self);
+    old_items.Sort({{u.name}}Comparer.self);
 
     int i = 0;
     int old_i = 0;
@@ -390,15 +401,13 @@ public class {{o.name}} : IRpc
       var old = old_items[old_i];
       var item = items[i];
 
-      if(old.getPrimaryId() < item.getPrimaryId())
+      if(old < item)
       {
-        var removed_ids = GetClassRemovedIds(removed, {{u.name}}.STATIC_CLASS_ID);
-        if(removed_ids != null)
-          removed_ids.Add(old.getPrimaryId());
+        removed.Add(old.MakeId());
         old_i++;
         has_diff = true;
       }
-      else if(old.getPrimaryId() > item.getPrimaryId())
+      else if(old > item)
       {
         item.SetDirtyMask();
         if(changed != null)
@@ -433,9 +442,7 @@ public class {{o.name}} : IRpc
     //old items leftovers are considered removed
     for(; old_i < old_items.Count; old_i++)
     {
-      var removed_ids = GetClassRemovedIds(removed, {{u.name}}.STATIC_CLASS_ID);
-      if(removed_ids != null)
-        removed_ids.Add(old_items[old_i].getPrimaryId());
+      removed.Add(old_items[old_i].MakeId());
       has_diff = true;
     }
 
@@ -447,25 +454,6 @@ public class {{o.name}} : IRpc
     return has_diff;
   }
 
-  class {{u.name}}Compare : IComparer<{{u.name}}>
-  {
-    public int Compare({{u.name}} o1, {{u.name}} o2)
-    { 
-      var id1 = o1.getPrimaryId();
-      var id2 = o2.getPrimaryId();
-      if(id1 == id2)
-        return 0;
-      return id1 > id2 ? 1 : -1;
-    }
-  }
-
-  static {{u.name}}Compare {{u.name}}_compare = new {{u.name}}Compare();
-
-  static void SortByPrimaryId(ref List<{{u.name}}> list)
-  {
-    list.Sort({{u.name}}_compare); 
-  }
-
   public static bool {{_self.compare_func_name(u)}}(ref {{u.name}} a, {{u.name}} b)
   {
     bool is_equal = true;
@@ -564,7 +552,7 @@ public class {{o.name}} : IRpc
 
   if(DiffCollection({{f.name}}, old.{{f.name}}, 
       diff == null ? null : diff.{{f.name}}, 
-      removed
+      removed == null ? null : removed.{{f.name}}
      )) 
   { 
     no_changes &= false;