diff --git a/src/db/db/dbDeepShapeStore.cc b/src/db/db/dbDeepShapeStore.cc
index 19f3a7255..4c32c396b 100644
--- a/src/db/db/dbDeepShapeStore.cc
+++ b/src/db/db/dbDeepShapeStore.cc
@@ -268,6 +268,16 @@ DeepShapeStore::DeepShapeStore ()
   ++s_instance_count;
 }
 
+DeepShapeStore::DeepShapeStore (const std::string &topcell_name, double dbu)
+  : m_threads (1), m_max_area_ratio (3.0), m_max_vertex_count (16), m_text_property_name (), m_text_enlargement (-1)
+{
+  ++s_instance_count;
+
+  m_layouts.push_back (new LayoutHolder (db::ICplxTrans ()));
+  m_layouts.back ()->layout.dbu (dbu);
+  m_layouts.back ()->layout.add_cell (topcell_name.c_str ());
+}
+
 DeepShapeStore::~DeepShapeStore ()
 {
   --s_instance_count;
@@ -278,6 +288,33 @@ DeepShapeStore::~DeepShapeStore ()
   m_layouts.clear ();
 }
 
+DeepLayer DeepShapeStore::create_from_flat (const db::Region &region, double max_area_ratio, size_t max_vertex_count, const db::ICplxTrans &trans)
+{
+  require_singular ();
+
+  unsigned int layer = layout ().insert_layer ();
+
+  if (max_area_ratio == 0.0) {
+    max_area_ratio = m_max_area_ratio;
+  }
+  if (max_vertex_count == 0) {
+    max_vertex_count = m_max_vertex_count;
+  }
+
+  db::Shapes *shapes = &initial_cell ().shapes (layer);
+  db::Box world = db::Box::world ();
+
+  //  The chain of operators for producing clipped and reduced polygon references
+  db::PolygonReferenceHierarchyBuilderShapeReceiver refs (&layout (), m_text_enlargement, m_text_property_name);
+  db::ReducingHierarchyBuilderShapeReceiver red (&refs, max_area_ratio, max_vertex_count);
+
+  for (db::Region::const_iterator p = region.begin (); ! p.at_end (); ++p) {
+    red.push (*p, trans, world, 0, shapes);
+  }
+
+  return DeepLayer (this, 0 /*singular layout index*/, layer);
+}
+
 bool DeepShapeStore::is_singular () const
 {
   return m_layouts.size () == 1;
diff --git a/src/db/db/dbDeepShapeStore.h b/src/db/db/dbDeepShapeStore.h
index 1f197d424..d08e47c3f 100644
--- a/src/db/db/dbDeepShapeStore.h
+++ b/src/db/db/dbDeepShapeStore.h
@@ -232,6 +232,14 @@ public:
    */
   DeepShapeStore ();
 
+  /**
+   *  @brief The constructor for a singular DSS
+   *
+   *  This DSS will be initialized with one layout and the given database unit
+   *  and top level cell name.
+   */
+  DeepShapeStore (const std::string &topcell_name, double dbu);
+
   /**
    *  @brief The destructor
    */
@@ -251,6 +259,14 @@ public:
    */
   bool is_singular () const;
 
+  /**
+   *  @brief Creates a new layer from a flat region (or the region is made flat)
+   *
+   *  This method is intended for use with singular-created DSS objects (see
+   *  singular constructor).
+   */
+  DeepLayer create_from_flat (const db::Region &region, double max_area_ratio = 0.0, size_t max_vertex_count = 0, const db::ICplxTrans &trans = db::ICplxTrans ());
+
   /**
    *  @brief Inserts a polygon layer into the deep shape store
    *
diff --git a/src/db/db/dbEdgePairsDelegate.h b/src/db/db/dbEdgePairsDelegate.h
index d894013b4..c7eb85082 100644
--- a/src/db/db/dbEdgePairsDelegate.h
+++ b/src/db/db/dbEdgePairsDelegate.h
@@ -27,6 +27,7 @@
 #include "dbCommon.h"
 
 #include "dbEdgePair.h"
+#include "tlUniqueId.h"
 
 namespace db {
 
@@ -58,6 +59,7 @@ public:
  *  @brief The delegate for the actual edge set implementation
  */
 class DB_PUBLIC EdgePairsDelegate
+  : public tl::UniqueId
 {
 public:
   typedef db::Coord coord_type;
diff --git a/src/db/db/dbEdgesDelegate.h b/src/db/db/dbEdgesDelegate.h
index 5bd4651dd..420e406e1 100644
--- a/src/db/db/dbEdgesDelegate.h
+++ b/src/db/db/dbEdgesDelegate.h
@@ -29,6 +29,7 @@
 #include "dbEdge.h"
 #include "dbEdgePairs.h"
 #include "dbEdgePairRelations.h"
+#include "tlUniqueId.h"
 
 #include <list>
 
@@ -185,6 +186,7 @@ public:
  *  @brief The delegate for the actual edge set implementation
  */
 class DB_PUBLIC EdgesDelegate
+  : public tl::UniqueId
 {
 public:
   typedef db::Coord coord_type;
diff --git a/src/db/db/dbLayoutToNetlist.cc b/src/db/db/dbLayoutToNetlist.cc
index bb7bd6549..04dfa6af7 100644
--- a/src/db/db/dbLayoutToNetlist.cc
+++ b/src/db/db/dbLayoutToNetlist.cc
@@ -38,7 +38,7 @@ static bool is_deep (const db::Region &r)
 //  the iterator provides the hierarchical selection (enabling/disabling cells etc.)
 
 LayoutToNetlist::LayoutToNetlist (const db::RecursiveShapeIterator &iter)
-  : m_iter (iter), m_netlist_extracted (false)
+  : m_iter (iter), m_netlist_extracted (false), m_is_flat (false)
 {
   //  check the iterator
   if (iter.has_complex_region () || iter.region () != db::Box::world ()) {
@@ -48,46 +48,68 @@ LayoutToNetlist::LayoutToNetlist (const db::RecursiveShapeIterator &iter)
   init ();
 }
 
+LayoutToNetlist::LayoutToNetlist (db::DeepShapeStore *dss, unsigned int layout_index)
+  : mp_dss (dss), m_netlist_extracted (false), m_is_flat (false)
+{
+  m_iter = db::RecursiveShapeIterator (dss->layout (layout_index), dss->initial_cell (layout_index), std::set<unsigned int> ());
+
+  init ();
+}
+
+LayoutToNetlist::LayoutToNetlist (const std::string &topcell_name, double dbu)
+  : m_iter (), m_netlist_extracted (false), m_is_flat (true)
+{
+  mp_internal_dss.reset (new db::DeepShapeStore (topcell_name, dbu));
+  mp_dss.reset (mp_internal_dss.get ());
+
+  init ();
+}
+
 LayoutToNetlist::LayoutToNetlist ()
-  : m_iter (), m_netlist_extracted (false)
+  : m_iter (), mp_internal_dss (new db::DeepShapeStore ()), mp_dss (mp_internal_dss.get ()), m_netlist_extracted (false), m_is_flat (true)
 {
   init ();
 }
 
 void LayoutToNetlist::init ()
 {
-  m_dss.set_text_enlargement (1);
-  m_dss.set_text_property_name (tl::Variant ("LABEL"));
+  if (! mp_dss.get ()) {
+    mp_internal_dss.reset (new db::DeepShapeStore ());
+    mp_dss.reset (mp_internal_dss.get ());
+  }
+
+  dss ().set_text_enlargement (1);
+  dss ().set_text_property_name (tl::Variant ("LABEL"));
 }
 
 void LayoutToNetlist::set_threads (int n)
 {
-  m_dss.set_threads (n);
+  dss ().set_threads (n);
 }
 
 int LayoutToNetlist::threads () const
 {
-  return m_dss.threads ();
+  return dss ().threads ();
 }
 
 void LayoutToNetlist::set_area_ratio (double ar)
 {
-  m_dss.set_max_area_ratio (ar);
+  dss ().set_max_area_ratio (ar);
 }
 
 double LayoutToNetlist::area_ratio () const
 {
-  return m_dss.max_area_ratio ();
+  return dss ().max_area_ratio ();
 }
 
 void LayoutToNetlist::set_max_vertex_count (size_t n)
 {
-  m_dss.set_max_vertex_count (n);
+  dss ().set_max_vertex_count (n);
 }
 
 size_t LayoutToNetlist::max_vertex_count () const
 {
-  return m_dss.max_vertex_count ();
+  return dss ().max_vertex_count ();
 }
 
 db::Region *LayoutToNetlist::make_layer (const std::string &n)
@@ -95,7 +117,7 @@ db::Region *LayoutToNetlist::make_layer (const std::string &n)
   db::RecursiveShapeIterator si (m_iter);
   si.shape_flags (db::ShapeIterator::Nothing);
 
-  std::auto_ptr <db::Region> region (new db::Region (si, m_dss));
+  std::auto_ptr <db::Region> region (new db::Region (si, dss ()));
   if (! n.empty ()) {
     register_layer (*region, n);
   }
@@ -108,7 +130,7 @@ db::Region *LayoutToNetlist::make_layer (unsigned int layer_index, const std::st
   si.set_layer (layer_index);
   si.shape_flags (db::ShapeIterator::All);
 
-  std::auto_ptr <db::Region> region (new db::Region (si, m_dss));
+  std::auto_ptr <db::Region> region (new db::Region (si, dss ()));
   if (! n.empty ()) {
     register_layer (*region, n);
   }
@@ -121,7 +143,7 @@ db::Region *LayoutToNetlist::make_text_layer (unsigned int layer_index, const st
   si.set_layer (layer_index);
   si.shape_flags (db::ShapeIterator::Texts);
 
-  std::auto_ptr <db::Region> region (new db::Region (si, m_dss));
+  std::auto_ptr <db::Region> region (new db::Region (si, dss ()));
   if (! n.empty ()) {
     register_layer (*region, n);
   }
@@ -134,7 +156,7 @@ db::Region *LayoutToNetlist::make_polygon_layer (unsigned int layer_index, const
   si.set_layer (layer_index);
   si.shape_flags (db::ShapeIterator::Paths | db::ShapeIterator::Polygons | db::ShapeIterator::Boxes);
 
-  std::auto_ptr <db::Region> region (new db::Region (si, m_dss));
+  std::auto_ptr <db::Region> region (new db::Region (si, dss ()));
   if (! n.empty ()) {
     register_layer (*region, n);
   }
@@ -149,7 +171,7 @@ void LayoutToNetlist::extract_devices (db::NetlistDeviceExtractor &extractor, co
   if (! mp_netlist.get ()) {
     mp_netlist.reset (new db::Netlist ());
   }
-  extractor.extract(m_dss, layers, *mp_netlist, m_net_clusters);
+  extractor.extract(dss (), layers, *mp_netlist, m_net_clusters);
 }
 
 void LayoutToNetlist::connect (const db::Region &l)
@@ -236,7 +258,7 @@ void LayoutToNetlist::extract_netlist (bool join_nets_by_label)
   }
 
   db::NetlistExtractor netex;
-  netex.extract_nets(m_dss, m_conn, *mp_netlist, m_net_clusters, join_nets_by_label);
+  netex.extract_nets(dss (), m_conn, *mp_netlist, m_net_clusters, join_nets_by_label);
 
   m_netlist_extracted = true;
 }
@@ -248,30 +270,30 @@ void LayoutToNetlist::set_netlist_extracted ()
 
 const db::Layout *LayoutToNetlist::internal_layout () const
 {
-  return &m_dss.const_layout ();
+  return &dss ().const_layout ();
 }
 
 const db::Cell *LayoutToNetlist::internal_top_cell () const
 {
-  return &m_dss.const_initial_cell ();
+  return &dss ().const_initial_cell ();
 }
 
 void LayoutToNetlist::ensure_internal_layout ()
 {
-  if (m_dss.layouts () == 0) {
+  if (dss ().layouts () == 0) {
     //  the dummy layer acts as a reference holder for the layout
-    m_dummy_layer = m_dss.create_polygon_layer (db::RecursiveShapeIterator ());
+    m_dummy_layer = dss ().create_polygon_layer (db::RecursiveShapeIterator ());
   }
 }
 
 db::Layout *LayoutToNetlist::internal_layout ()
 {
-  return &m_dss.layout ();
+  return &dss ().layout ();
 }
 
 db::Cell *LayoutToNetlist::internal_top_cell ()
 {
-  return &m_dss.initial_cell ();
+  return &dss ().initial_cell ();
 }
 
 void LayoutToNetlist::register_layer (const db::Region &region, const std::string &n)
@@ -280,18 +302,38 @@ void LayoutToNetlist::register_layer (const db::Region &region, const std::strin
     throw tl::Exception (tl::to_string (tr ("Layer name is already used: ")) + n);
   }
 
-  db::DeepRegion *delegate = dynamic_cast<db::DeepRegion *> (region.delegate());
-  if (! delegate) {
-    throw tl::Exception (tl::to_string (tr ("Layer is not a deep region")));
+  db::DeepLayer dl;
+
+  if (m_is_flat) {
+
+    dl = dss ().create_from_flat (region);
+
+  } else {
+
+    db::DeepRegion *delegate = dynamic_cast<db::DeepRegion *> (region.delegate());
+    if (! delegate) {
+
+      if (region.empty ()) {
+        dl = dss ().empty_layer ();
+      } else {
+        throw tl::Exception (tl::to_string (tr ("Layer is not a deep region")));
+      }
+
+    } else {
+
+      if (is_persisted (region)) {
+        std::string prev_name = name (region);
+        m_named_regions.erase (prev_name);
+      }
+
+      dl = delegate->deep_layer ();
+
+    }
+
   }
 
-  if (is_persisted (region)) {
-    std::string prev_name = name (region);
-    m_named_regions.erase (prev_name);
-  }
-
-  m_named_regions [n] = delegate->deep_layer ();
-  m_name_of_layer [layer_of (region)] = n;
+  m_named_regions [n] = dl;
+  m_name_of_layer [dl.layer ()] = n;
 }
 
 std::string LayoutToNetlist::name (const db::Region &region) const
@@ -359,7 +401,7 @@ db::CellMapping LayoutToNetlist::cell_mapping_into (db::Layout &layout, db::Cell
     }
   }
 
-  return m_dss.cell_mapping_to_original (layout_index, &layout, cell.cell_index (), &device_cells);
+  return dss ().cell_mapping_to_original (layout_index, &layout, cell.cell_index (), &device_cells);
 }
 
 db::CellMapping LayoutToNetlist::const_cell_mapping_into (const db::Layout &layout, const db::Cell &cell)
diff --git a/src/db/db/dbLayoutToNetlist.h b/src/db/db/dbLayoutToNetlist.h
index 30a46063d..3c57b9c7a 100644
--- a/src/db/db/dbLayoutToNetlist.h
+++ b/src/db/db/dbLayoutToNetlist.h
@@ -82,6 +82,28 @@ public:
    */
   LayoutToNetlist (const db::RecursiveShapeIterator &iter);
 
+  /**
+   *  @brief Alternative constructor using an external deep shape storage
+   *
+   *  This constructor allows using an external DSS. It's intended to be used
+   *  with existing DSS instances. Existing layers can be registered with
+   *  "register_layer". The LayoutToNetlist object will hold a weak reference
+   *  to the DSS but not own the DSS.
+   *
+   *  NOTE: if using make_layer, these new layers will be created in the DSS
+   *  given in this constructor.
+   */
+  LayoutToNetlist (db::DeepShapeStore *dss, unsigned int layout_index);
+
+  /**
+   *  @brief Alternative constructor for flat mode
+   *
+   *  In flat mode, the internal DSS will be initialized to a top-level only
+   *  layout. All layers entered through "register_layer" or created with
+   *  "make_layer" will become flat ones.
+   */
+  LayoutToNetlist (const std::string &topcell_name, double dbu);
+
   /**
    *  @brief The default constructor
    */
@@ -467,7 +489,8 @@ private:
   LayoutToNetlist &operator= (const db::LayoutToNetlist &other);
 
   db::RecursiveShapeIterator m_iter;
-  db::DeepShapeStore m_dss;
+  std::auto_ptr<db::DeepShapeStore> mp_internal_dss;
+  tl::weak_ptr<db::DeepShapeStore> mp_dss;
   db::Connectivity m_conn;
   db::hier_clusters<db::PolygonRef> m_net_clusters;
   std::auto_ptr<db::Netlist> mp_netlist;
@@ -475,8 +498,21 @@ private:
   std::map<std::string, db::DeepLayer> m_named_regions;
   std::map<unsigned int, std::string> m_name_of_layer;
   bool m_netlist_extracted;
+  bool m_is_flat;
   db::DeepLayer m_dummy_layer;
 
+  db::DeepShapeStore &dss ()
+  {
+    tl_assert (mp_dss.get () != 0);
+    return *mp_dss;
+  }
+
+  const db::DeepShapeStore &dss () const
+  {
+    tl_assert (mp_dss.get () != 0);
+    return *mp_dss;
+  }
+
   void init ();
   size_t search_net (const db::ICplxTrans &trans, const db::Cell *cell, const db::local_cluster<db::PolygonRef> &test_cluster, std::vector<db::InstElement> &rev_inst_path);
   void build_net_rec (const db::Net &net, db::Layout &target, db::Cell &target_cell, const std::map<unsigned int, const db::Region *> &lmap, const char *net_cell_name_prefix, const char *cell_name_prefix, const char *device_cell_name_prefix, std::map<std::pair<db::cell_index_type, size_t>, db::cell_index_type> &cmap, const ICplxTrans &tr) const;
diff --git a/src/db/db/dbRegionDelegate.h b/src/db/db/dbRegionDelegate.h
index fbeb35198..f5eb945d7 100644
--- a/src/db/db/dbRegionDelegate.h
+++ b/src/db/db/dbRegionDelegate.h
@@ -30,6 +30,7 @@
 #include "dbEdges.h"
 #include "dbEdgePairs.h"
 #include "dbEdgePairRelations.h"
+#include "tlUniqueId.h"
 
 #include <list>
 
@@ -181,6 +182,7 @@ public:
  *  @brief The delegate for the actual region implementation
  */
 class DB_PUBLIC RegionDelegate
+  : public tl::UniqueId
 {
 public:
   typedef db::Coord coord_type;
diff --git a/src/db/db/gsiDeclDbDeepShapeStore.cc b/src/db/db/gsiDeclDbDeepShapeStore.cc
index 77ac2fc30..471c6fe67 100644
--- a/src/db/db/gsiDeclDbDeepShapeStore.cc
+++ b/src/db/db/gsiDeclDbDeepShapeStore.cc
@@ -30,6 +30,13 @@ Class<db::DeepShapeStore> decl_dbDeepShapeStore ("db", "DeepShapeStore",
   gsi::method ("instance_count", &db::DeepShapeStore::instance_count,
     "@hide\n"
   ) +
+  gsi::method ("is_singular?", &db::DeepShapeStore::is_singular,
+    "@brief Gets a value indicating whether there is a single layout variant\n"
+    "\n"
+    "Specifically for network extraction, singular DSS objects are required. "
+    "Multiple layouts may be present if different sources of layouts have "
+    "been used. Such DSS objects are not usable for network extraction."
+  ) +
   gsi::method ("threads=", &db::DeepShapeStore::set_threads, gsi::arg ("n"),
     "@brief Sets the number of threads to allocate for the hierarchical processor\n"
   ) +
diff --git a/src/db/db/gsiDeclDbEdgePairs.cc b/src/db/db/gsiDeclDbEdgePairs.cc
index 62e20011e..6bef742c6 100644
--- a/src/db/db/gsiDeclDbEdgePairs.cc
+++ b/src/db/db/gsiDeclDbEdgePairs.cc
@@ -174,6 +174,11 @@ static bool is_deep (const db::EdgePairs *ep)
   return dynamic_cast<const db::DeepEdgePairs *> (ep->delegate ()) != 0;
 }
 
+static size_t id (const db::EdgePairs *ep)
+{
+  return tl::id_of (ep->delegate ());
+}
+
 Class<db::EdgePairs> decl_EdgePairs ("db", "EdgePairs",
   constructor ("new", &new_v, 
     "@brief Default constructor\n"
@@ -312,6 +317,11 @@ Class<db::EdgePairs> decl_EdgePairs ("db", "EdgePairs",
     "\n"
     "This method has been added in version 0.26."
   ) +
+  method_ext ("data_id", &id,
+    "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
+    "\n"
+    "This method has been added in version 0.26."
+  ) +
   method ("+", &db::EdgePairs::operator+,
     "@brief Returns the combined edge pair collection of self and the other one\n"
     "\n"
diff --git a/src/db/db/gsiDeclDbEdges.cc b/src/db/db/gsiDeclDbEdges.cc
index 1cf48d1cf..39163911a 100644
--- a/src/db/db/gsiDeclDbEdges.cc
+++ b/src/db/db/gsiDeclDbEdges.cc
@@ -400,6 +400,10 @@ static db::Edges *new_texts_as_dots2 (const db::RecursiveShapeIterator &si, db::
   return new db::Edges (db::OriginalLayerRegion (si, false).texts_as_dots (pat, pattern, dss));
 }
 
+static size_t id (const db::Edges *e)
+{
+  return tl::id_of (e->delegate ());
+}
 
 Class<db::Edges> dec_Edges ("db", "Edges",
   constructor ("new", &new_v, 
@@ -1466,6 +1470,11 @@ Class<db::Edges> dec_Edges ("db", "Edges",
     "\n"
     "This method has been added in version 0.26."
   ) +
+  method_ext ("data_id", &id,
+    "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
+    "\n"
+    "This method has been added in version 0.26."
+  ) +
   method ("is_merged?", &db::Edges::is_merged,
     "@brief Returns true if the edge collection is merged\n"
     "If the region is merged, coincident edges have been merged into single edges. You can ensure merged state "
diff --git a/src/db/db/gsiDeclDbLayoutToNetlist.cc b/src/db/db/gsiDeclDbLayoutToNetlist.cc
index 153b6601b..37dc8650f 100644
--- a/src/db/db/gsiDeclDbLayoutToNetlist.cc
+++ b/src/db/db/gsiDeclDbLayoutToNetlist.cc
@@ -39,6 +39,16 @@ static db::LayoutToNetlist *make_l2n_default ()
   return new db::LayoutToNetlist ();
 }
 
+static db::LayoutToNetlist *make_l2n_from_existing_dss (db::DeepShapeStore *dss, unsigned int layout_index)
+{
+  return new db::LayoutToNetlist (dss, layout_index);
+}
+
+static db::LayoutToNetlist *make_l2n_flat (const std::string &topcell_name, double dbu)
+{
+  return new db::LayoutToNetlist (topcell_name, dbu);
+}
+
 static db::Layout *l2n_internal_layout (db::LayoutToNetlist *l2n)
 {
   //  although this isn't very clean, we dare to do so as const references are pretty useless in script languages.
@@ -99,6 +109,24 @@ Class<db::LayoutToNetlist> decl_dbLayoutToNetlist ("db", "LayoutToNetlist",
     "@brief Creates a new and empty extractor object\n"
     "The main objective for this constructor is to create an object suitable for reading an annotated netlist.\n"
   ) +
+  gsi::constructor ("new", &make_l2n_from_existing_dss, gsi::arg ("dss"), gsi::arg ("layout_index", 0),
+    "@brief Creates a new extractor object reusing an existing \\DeepShapeStore object\n"
+    "This constrcutor can be used if there is a DSS object already from which the "
+    "shapes can be taken. NOTE: in this case, the make_... functions will create "
+    "new layers inside this DSS. To register existing layers (regions) use \\register.\n"
+  ) +
+  gsi::constructor ("new", &make_l2n_flat, gsi::arg ("topcell_name"), gsi::arg ("dbu"),
+    "@brief Creates a new extractor object with a flat DSS\n"
+    "@param topcell_name The name of the top cell of the internal flat layout\n"
+    "@param dbu The database unit to use for the internal flat layout\n"
+    "\n"
+    "This constructor will create an extractor for flat extraction. Layers registered "
+    "with \\register will be flattened. New layers created with make_... will be flat "
+    "layers.\n"
+    "\n"
+    "The database unit is mandatory because the physical parameter extraction "
+    "for devices requires this unit for translation of layout to physical dimensions.\n"
+  ) +
   gsi::method ("threads=", &db::LayoutToNetlist::set_threads, gsi::arg ("n"),
     "@brief Sets the number of threads to use for operations which support multiple threads\n"
   ) +
@@ -382,6 +410,10 @@ Class<db::LayoutToNetlist> decl_dbLayoutToNetlist ("db", "LayoutToNetlist",
   "    finding a net by probing a specific location.\n"
   "@li\n"
   "\n"
+  "Another use model is using the extractor with an existing \\DeepShapeStore object "
+  "or even flat data. In this case, the preparation step is importing by "
+  "taking existing region data using the \\register method.\n"
+  "\n"
   "This class has been introduced in version 0.26."
 );
 
diff --git a/src/db/db/gsiDeclDbRegion.cc b/src/db/db/gsiDeclDbRegion.cc
index e55c1ba9d..78f7e41e4 100644
--- a/src/db/db/gsiDeclDbRegion.cc
+++ b/src/db/db/gsiDeclDbRegion.cc
@@ -600,6 +600,11 @@ static bool is_deep (const db::Region *region)
   return dynamic_cast<const db::DeepRegion *> (region->delegate ()) != 0;
 }
 
+static size_t id (const db::Region *r)
+{
+  return tl::id_of (r->delegate ());
+}
+
 //  provided by gsiDeclDbPolygon.cc:
 int td_simple ();
 int po_any ();
@@ -2231,6 +2236,11 @@ Class<db::Region> decl_Region ("db", "Region",
     "\n"
     "This method has been added in version 0.26."
   ) +
+  method_ext ("data_id", &id,
+    "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
+    "\n"
+    "This method has been added in version 0.26."
+  ) +
   method ("is_merged?", &db::Region::is_merged,
     "@brief Returns true if the region is merged\n"
     "If the region is merged, polygons will not touch or overlap. You can ensure merged state "
diff --git a/testdata/ruby/dbEdgePairsTest.rb b/testdata/ruby/dbEdgePairsTest.rb
index ba029ec51..5df2cc5f1 100644
--- a/testdata/ruby/dbEdgePairsTest.rb
+++ b/testdata/ruby/dbEdgePairsTest.rb
@@ -33,8 +33,10 @@ class DBEdgePairs_TestClass < TestBase
     assert_equal(r.is_empty?, true)
     assert_equal(r.size, 0)
     assert_equal(r.bbox.to_s, "()")
+    data_id = r.data_id
 
     r.insert(RBA::Edge::new(0, 0, 0, 100), RBA::Edge::new(-10, 0, -20, 50))
+    assert_equal(data_id != r.data_id, true)
     assert_equal(r.to_s, "(0,0;0,100)/(-10,0;-20,50)")
     r.clear
 
@@ -55,6 +57,7 @@ class DBEdgePairs_TestClass < TestBase
     assert_equal(r.moved(-10, 10).to_s, "(-10,10;-10,110)/(-20,10;-30,60)")
     assert_equal(r.moved(RBA::Point::new(-10, 10)).to_s, "(-10,10;-10,110)/(-20,10;-30,60)")
     rr = r.dup
+    assert_equal(rr.data_id != r.data_id, true)
     rr.move(-10, 10)
     assert_equal(rr.to_s, "(-10,10;-10,110)/(-20,10;-30,60)")
     rr = r.dup
diff --git a/testdata/ruby/dbEdgesTest.rb b/testdata/ruby/dbEdgesTest.rb
index 52e3c9062..9b3435200 100644
--- a/testdata/ruby/dbEdgesTest.rb
+++ b/testdata/ruby/dbEdgesTest.rb
@@ -34,8 +34,10 @@ class DBEdges_TestClass < TestBase
     assert_equal(r.size, 0)
     assert_equal(r.bbox.to_s, "()")
     assert_equal(r.is_merged?, true)
+    data_id = r.data_id
     
     r.assign(RBA::Edges::new([RBA::Edge::new(10, 20, 100, 200)]))
+    assert_equal(data_id != r.data_id, true)
     assert_equal(r.to_s, "(10,20;100,200)")
     assert_equal(r.is_empty?, false)
     assert_equal(r.size, 1)
@@ -72,6 +74,7 @@ class DBEdges_TestClass < TestBase
     assert_equal(r.moved(RBA::Point::new(10, 20)).bbox.to_s, "(20,40;110,220)")
     assert_equal(r.moved(10, 20).bbox.to_s, "(20,40;110,220)")
     rr = r.dup
+    assert_equal(rr.data_id != r.data_id, true)
     rr.move(RBA::Point::new(10, 20))
     assert_equal(rr.bbox.to_s, "(20,40;110,220)")
     rr = r.dup
diff --git a/testdata/ruby/dbRegionTest.rb b/testdata/ruby/dbRegionTest.rb
index ec04f7d2d..92f10f144 100644
--- a/testdata/ruby/dbRegionTest.rb
+++ b/testdata/ruby/dbRegionTest.rb
@@ -35,8 +35,10 @@ class DBRegion_TestClass < TestBase
     assert_equal(r.bbox.to_s, "()")
     assert_equal(r.is_merged?, true)
     assert_equal(r.is_box?, false)
+    data_id = r.data_id
     
     r.assign(RBA::Region::new(RBA::Box::new(10, 20, 100, 200)))
+    assert_equal(data_id != r.data_id, true)
     assert_equal(r.to_s, "(10,20;10,200;100,200;100,20)")
     assert_equal(r.is_empty?, false)
     assert_equal(r.size, 1)
@@ -48,6 +50,7 @@ class DBRegion_TestClass < TestBase
     assert_equal(r.moved(RBA::Point::new(10, 20)).bbox.to_s, "(20,40;110,220)")
     assert_equal(r.moved(10, 20).bbox.to_s, "(20,40;110,220)")
     rr = r.dup
+    assert_equal(rr.data_id != r.data_id, true)
     rr.move(RBA::Point::new(10, 20))
     assert_equal(rr.bbox.to_s, "(20,40;110,220)")
     rr = r.dup