diff --git a/include/osgDB/DatabasePager b/include/osgDB/DatabasePager
index 55b30abc2..3294356dd 100644
--- a/include/osgDB/DatabasePager
+++ b/include/osgDB/DatabasePager
@@ -148,7 +148,7 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         /** Find all PagedLOD nodes in a subgraph and register them with 
           * the DatabasePager so it can keep track of expired nodes.
           * note, should be only be called from the update thread. */
-        virtual void registerPagedLODs(osg::Node* subgraph);
+        virtual void registerPagedLODs(osg::Node* subgraph, int frameNumber = 0);
 
         /** Set whether the database pager should pre compile OpenGL objects before allowing
           * them to be merged into the scene graph.
@@ -272,7 +272,7 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         
         /** Merge the changes to the scene graph by calling calling removeExpiredSubgraphs then addLoadedDataToSceneGraph.
           * Note, must only be called from single thread update phase. */
-        virtual void updateSceneGraph(const osg::FrameStamp &frameStamp)
+        virtual void updateSceneGraph(const osg::FrameStamp& frameStamp)
         {
             removeExpiredSubgraphs(frameStamp);
             addLoadedDataToSceneGraph(frameStamp);
@@ -514,6 +514,12 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
           * note, should be only be called from the update thread. */
         virtual void removeExpiredSubgraphs(const osg::FrameStamp &frameStamp);
 
+        /** Old expiry delay based removeExpiredSubgraphs. */
+        virtual void expiry_removeExpiredSubgraphs(const osg::FrameStamp &frameStamp);
+
+        /** New capped based removeExpiredSubgraphs. */
+        virtual void capped_removeExpiredSubgraphs(const osg::FrameStamp &frameStamp);
+
         /** Add the loaded data to the scene graph.*/
         void addLoadedDataToSceneGraph(const osg::FrameStamp &frameStamp);
 
@@ -545,8 +551,11 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
 
         osg::ref_ptr<RequestQueue>      _dataToMergeList;
         
-        PagedLODList                    _pagedLODList;
+        PagedLODList                    _activePagedLODList;
+        PagedLODList                    _inactivePagedLODList;
         
+        unsigned int                    _maximumNumberOfPageLOD;
+
         double                          _expiryDelay;
         int                             _expiryFrames;
 
diff --git a/src/osgDB/DatabasePager.cpp b/src/osgDB/DatabasePager.cpp
index b4c26fd1e..5a2d366d9 100644
--- a/src/osgDB/DatabasePager.cpp
+++ b/src/osgDB/DatabasePager.cpp
@@ -856,6 +856,7 @@ DatabasePager::DatabasePager()
     {
         setReleaseDelay(DBL_MAX);
     }
+    
 
     _releaseFrames = 1; // Last frame will not be release
     if( (ptr = getenv("OSG_RELEASE_FRAMES")) != 0)
@@ -864,6 +865,17 @@ DatabasePager::DatabasePager()
         osg::notify(osg::NOTICE)<<"Release frames = "<<_releaseFrames<<std::endl;
     }
 
+
+    _maximumNumberOfPageLOD = 0;
+    if( (ptr = getenv("OSG_MAX_PAGEDLOD")) != 0)
+    {
+        _maximumNumberOfPageLOD = atoi(ptr);
+        osg::notify(osg::NOTICE)<<"_maximumNumberOfPageLOD = "<<_maximumNumberOfPageLOD<<std::endl;
+    }
+
+
+
+
     _doPreCompile = true;
     if( (ptr = getenv("OSG_DO_PRE_COMPILE")) != 0)
     {
@@ -945,6 +957,8 @@ DatabasePager::DatabasePager(const DatabasePager& rhs)
     _releaseDelay = rhs._releaseDelay;
     _releaseFrames = rhs._releaseFrames;
 
+    _maximumNumberOfPageLOD = rhs._maximumNumberOfPageLOD;
+
     _doPreCompile = rhs._doPreCompile;
     _targetFrameRate = rhs._targetFrameRate;
     _minimumTimeAvailableForGLCompileAndDeletePerFrame = rhs._minimumTimeAvailableForGLCompileAndDeletePerFrame;
@@ -1086,7 +1100,8 @@ void DatabasePager::clear()
     }
 
     // note, no need to use a mutex as the list is only accessed from the update thread.
-    _pagedLODList.clear();
+    _activePagedLODList.clear();
+    _inactivePagedLODList.clear();
 
     // ??
     // _activeGraphicsContexts
@@ -1300,7 +1315,7 @@ void DatabasePager::addLoadedDataToSceneGraph(const osg::FrameStamp &frameStamp)
             osgDB::Registry::instance()->getSharedStateManager()->share(databaseRequest->_loadedModel.get());
 
         
-        registerPagedLODs(databaseRequest->_loadedModel.get());
+        registerPagedLODs(databaseRequest->_loadedModel.get(), frameStamp.getFrameNumber());
         
         osg::ref_ptr<osg::Group> group = databaseRequest->_groupForAddingLoadedSubgraph.get();
         if (group.valid())
@@ -1349,25 +1364,302 @@ class DatabasePager::MarkPagedLODsVisitor : public osg::NodeVisitor
 public:
     MarkPagedLODsVisitor(const std::string& marker):
         osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
-        _marker(marker)
+        _marker(marker),
+        _numPagedLODsMarked(0)
     {
     }
 
     virtual void apply(osg::PagedLOD& plod)
     {
-        plod.setName(_marker);
+        if (plod.getName()!=_marker)
+        {
+            ++_numPagedLODsMarked;
+            plod.setName(_marker);
     
-        traverse(plod);
+            traverse(plod);
+        }
     }
     
     std::string _marker;
+    unsigned int _numPagedLODsMarked;
 };
 
-void DatabasePager::removeExpiredSubgraphs(const osg::FrameStamp &frameStamp)
+void DatabasePager::removeExpiredSubgraphs(const osg::FrameStamp& frameStamp)
+{
+    if (_maximumNumberOfPageLOD>0)
+    {
+        capped_removeExpiredSubgraphs(frameStamp);
+    }
+    else
+    {
+        expiry_removeExpiredSubgraphs(frameStamp);
+    }
+}
+
+void DatabasePager::capped_removeExpiredSubgraphs(const osg::FrameStamp& frameStamp)
+{
+    static double s_total_iter_stage_a = 0.0;
+    static double s_total_time_stage_a = 0.0;
+    static double s_total_max_stage_a = 0.0;
+    
+    static double s_total_iter_stage_b = 0.0;
+    static double s_total_time_stage_b = 0.0;
+    static double s_total_max_stage_b = 0.0;
+
+    static double s_total_iter_stage_c = 0.0;
+    static double s_total_time_stage_c = 0.0;
+    static double s_total_max_stage_c = 0.0;
+
+    osg::Timer_t startTick = osg::Timer::instance()->tick();
+
+
+#if 1
+
+    unsigned int numPagedLODs = _activePagedLODList.size() + _inactivePagedLODList.size();
+    
+
+    PagedLODList::iterator itr = _activePagedLODList.begin();
+    for(PagedLODList::iterator itr = _activePagedLODList.begin();
+        itr != _activePagedLODList.end();
+        )
+    {
+        osg::PagedLOD* plod = itr->get();
+        
+        int delta = frameStamp.getFrameNumber() - plod->getFrameNumberOfLastTraversal();
+        if (delta>1)
+        {
+            if (_releaseDelay!=DBL_MAX)
+            {
+                plod->releaseGLObjects();
+                osg::notify(osg::INFO)<<"DatabasePager::removeExpiredSubgraphs(), releasing gl objects"<<std::endl;
+            }
+
+            _inactivePagedLODList.push_back(plod);
+            
+            itr = _activePagedLODList.erase(itr);
+        }
+        else
+        {
+            ++itr;
+        }
+    }
+
+    for(PagedLODList::iterator itr = _inactivePagedLODList.begin();
+        itr != _inactivePagedLODList.end();
+        )
+    {
+        osg::PagedLOD* plod = itr->get();
+        
+        int delta = frameStamp.getFrameNumber() - plod->getFrameNumberOfLastTraversal();
+        if (delta>1)
+        {
+            ++itr;
+        }
+        else
+        {
+            _activePagedLODList.push_back(plod);
+            
+            itr = _inactivePagedLODList.erase(itr);
+        }
+    }
+
+    unsigned int inactivePLOD = _inactivePagedLODList.size();
+    unsigned int activePLOD = _activePagedLODList.size();
+
+    PagedLODList& pagedLODList = _inactivePagedLODList;
+    
+#else
+
+    unsigned int inactivePLOD = 0;
+    unsigned int activePLOD = 0;
+
+    // iterate through the PagedLOD list moving all newly traversed nodes to end of list
+    // leaving inactive ones in place, so they in effect shuffle to the front, with the least
+    // recently traversed placed at the front
+    unsigned int numPagedLODs = _activePagedLODList.size();
+    PagedLODList::iterator itr = _activePagedLODList.begin();
+    for(unsigned int numIterations = 0;
+        numIterations < numPagedLODs;
+        ++numIterations)
+    {
+        osg::PagedLOD* plod = itr->get();
+        
+        int delta = frameStamp.getFrameNumber() - plod->getFrameNumberOfLastTraversal();
+        if (delta>1)
+        {
+            ++inactivePLOD;
+            ++itr;
+        }
+        else
+        {
+            ++activePLOD;
+        
+            _activePagedLODList.push_back(plod);
+            
+            itr = _activePagedLODList.erase(itr);
+        }
+    }
+
+    PagedLODList& pagedLODList = _activePagedLODList;
+#endif    
+
+    osg::Timer_t end_a_Tick = osg::Timer::instance()->tick();
+    double time_a = osg::Timer::instance()->delta_m(startTick,end_a_Tick);
+
+    s_total_iter_stage_a += 1.0;
+    s_total_time_stage_a += time_a;
+    if (s_total_max_stage_a<time_a) s_total_max_stage_a = time_a;
+    
+
+    if (numPagedLODs <= _maximumNumberOfPageLOD)
+    {
+        // nothing to do
+        return;
+    }
+    
+    int numToPrune = numPagedLODs - _maximumNumberOfPageLOD;
+    if (numToPrune > inactivePLOD)
+    {
+        numToPrune = inactivePLOD;
+    }
+
+    osg::NodeList childrenRemoved;
+    
+    double expiryTime = frameStamp.getReferenceTime() - 0.1;
+    int expiryFrame = frameStamp.getFrameNumber() - 1;
+
+    MarkPagedLODsVisitor markerVistor("NeedToRemove");
+
+
+    for(PagedLODList::iterator itr = pagedLODList.begin();
+        itr!=pagedLODList.end() && markerVistor._numPagedLODsMarked<numToPrune;
+        ++itr)
+    {
+        osg::PagedLOD* plod = itr->get();
+
+        osg::NodeList localChildrenRemoved;
+        plod->removeExpiredChildren(expiryTime, expiryFrame, localChildrenRemoved);
+        if (!localChildrenRemoved.empty())
+        {
+            for(osg::NodeList::iterator critr = localChildrenRemoved.begin();
+                critr!=localChildrenRemoved.end();
+                ++critr)
+            {
+                (*critr)->accept(markerVistor);
+            }
+            
+            std::copy(localChildrenRemoved.begin(),localChildrenRemoved.end(),std::back_inserter(childrenRemoved));
+        }
+    }
+    
+    osg::Timer_t end_b_Tick = osg::Timer::instance()->tick();
+    double time_b = osg::Timer::instance()->delta_m(end_a_Tick,end_b_Tick);
+
+    s_total_iter_stage_b += 1.0;
+    s_total_time_stage_b += time_b;
+    if (s_total_max_stage_b<time_b) s_total_max_stage_b = time_b;
+
+    bool updateBlock = false;
+
+
+    if (!childrenRemoved.empty())
+    { 
+        // pass the objects across to the database pager delete list
+        if (_deleteRemovedSubgraphsInDatabaseThread)
+        {
+            OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_fileRequestQueue->_childrenToDeleteListMutex);
+            for (osg::NodeList::iterator critr = childrenRemoved.begin();
+                 critr!=childrenRemoved.end();
+                 ++critr)
+            {
+                _fileRequestQueue->_childrenToDeleteList.push_back(critr->get());
+            }
+            
+            updateBlock = true;
+
+        }
+
+        unsigned int numRemoved = 0;
+        unsigned int numToRemove = markerVistor._numPagedLODsMarked;
+        
+        
+        // osg::notify(osg::NOTICE)<<"Children to remove "<<childrenRemoved.size()<<" numToRemove="<<numToRemove<<std::endl;
+
+        // osg::notify(osg::NOTICE)<<"   time 2 "<<osg::Timer::instance()->delta_m(before,osg::Timer::instance()->tick())<<" ms "<<std::endl;
+        int numSkipped = 0;
+        for(PagedLODList::iterator itr = pagedLODList.begin();
+            itr!=pagedLODList.end() && numRemoved<numToRemove;
+            )
+        {
+            osg::PagedLOD* plod = itr->get();
+            if (plod && plod->getName() != markerVistor._marker)
+            {
+                ++itr;
+                
+                ++numSkipped;
+                
+                //osg::notify(osg::NOTICE)<<"skipping"<<std::endl;
+            }
+            else
+            {
+                //osg::notify(osg::NOTICE)<<"removing"<<std::endl;
+
+                ++numRemoved;
+
+                PagedLODList::iterator itr_to_erase = itr;
+                ++itr;
+
+                _activePagedLODList.erase(itr_to_erase);
+            }
+        }
+
+        // osg::notify(osg::NOTICE)<<"Number of PagedLODs skipped="<<numSkipped<<" removed "<<numRemoved<<std::endl;
+
+
+        childrenRemoved.clear();
+
+
+        if (updateBlock)
+        {
+            _fileRequestQueue->updateBlock();
+        }
+    }
+    
+    osg::Timer_t end_c_Tick = osg::Timer::instance()->tick();
+    double time_c = osg::Timer::instance()->delta_m(end_b_Tick,end_c_Tick);
+
+    s_total_iter_stage_c += 1.0;
+    s_total_time_stage_c += time_c;
+    if (s_total_max_stage_c<time_c) s_total_max_stage_c = time_c;
+
+
+    osg::Timer_t endTick = osg::Timer::instance()->tick();
+
+
+
+    osg::notify(osg::INFO)<<"active="<<_activePagedLODList.size()<<" inactive="<<_inactivePagedLODList.size()<<" overall = "<<osg::Timer::instance()->delta_m(startTick,end_c_Tick)<<
+                              " A="<<time_a<<" avg="<<s_total_time_stage_a/s_total_iter_stage_a<<" max = "<<s_total_max_stage_a<<
+                              " B="<<time_b<<" avg="<<s_total_time_stage_b/s_total_iter_stage_b<<" max = "<<s_total_max_stage_b<<
+                              " C="<<time_c<<" avg="<<s_total_time_stage_c/s_total_iter_stage_c<<" max = "<<s_total_max_stage_c<<std::endl;
+
+    
+    if (osgDB::Registry::instance()->getSharedStateManager()) 
+        osgDB::Registry::instance()->getSharedStateManager()->prune();
+
+    // update the Registry object cache.
+    osgDB::Registry::instance()->updateTimeStampOfObjectsInCacheWithExternalReferences(frameStamp.getReferenceTime());
+    osgDB::Registry::instance()->removeExpiredObjectsInCache(expiryTime);
+}
+
+void DatabasePager::expiry_removeExpiredSubgraphs(const osg::FrameStamp& frameStamp)
 {
 //    osg::notify(osg::NOTICE)<<"DatabasePager::new_removeExpiredSubgraphs()"<<std::endl;
 
+    static double s_total_iter = 0.0;
+    static double s_total_time = 0.0;
+    static double s_total_max = 0.0;
     
+    osg::Timer_t startTick = osg::Timer::instance()->tick();
 
     double expiryTime = frameStamp.getReferenceTime() - _expiryDelay;
     int expiryFrame = frameStamp.getFrameNumber() - _expiryFrames;
@@ -1377,8 +1669,8 @@ void DatabasePager::removeExpiredSubgraphs(const osg::FrameStamp &frameStamp)
 
     osg::NodeList childrenRemoved;
     
-    for(PagedLODList::iterator itr = _pagedLODList.begin();
-        itr!=_pagedLODList.end();
+    for(PagedLODList::iterator itr = _activePagedLODList.begin();
+        itr!=_activePagedLODList.end();
         ++itr)
     {
         osg::PagedLOD* plod = itr->get();
@@ -1419,8 +1711,8 @@ void DatabasePager::removeExpiredSubgraphs(const osg::FrameStamp &frameStamp)
         }
 
         // osg::notify(osg::NOTICE)<<"   time 2 "<<osg::Timer::instance()->delta_m(before,osg::Timer::instance()->tick())<<" ms "<<std::endl;
-        for(PagedLODList::iterator itr = _pagedLODList.begin();
-            itr!=_pagedLODList.end();
+        for(PagedLODList::iterator itr = _activePagedLODList.begin();
+            itr!=_activePagedLODList.end();
             )
         {
             osg::PagedLOD* plod = itr->get();
@@ -1433,15 +1725,26 @@ void DatabasePager::removeExpiredSubgraphs(const osg::FrameStamp &frameStamp)
                 PagedLODList::iterator itr_to_erase = itr;
                 ++itr;
 
-                _pagedLODList.erase(itr_to_erase);            
+                _activePagedLODList.erase(itr_to_erase);            
             }
         }
 
         childrenRemoved.clear();
 
+
     }
 
-    
+    osg::Timer_t endTick = osg::Timer::instance()->tick();
+    double time = osg::Timer::instance()->delta_m(startTick,endTick);
+
+    s_total_iter += 1.0;
+    s_total_time += time;
+    if (s_total_max<time) s_total_max = time;
+
+    osg::notify(osg::NOTICE)<<"_activePagedLODList.size()="<<_activePagedLODList.size()<<" overall = "<<time<<
+                              " avg="<<s_total_time/s_total_iter<<" max = "<<s_total_max<<std::endl;
+     
+   
     if (osgDB::Registry::instance()->getSharedStateManager()) 
         osgDB::Registry::instance()->getSharedStateManager()->prune();
 
@@ -1456,27 +1759,31 @@ class DatabasePager::FindPagedLODsVisitor : public osg::NodeVisitor
 {
 public:
 
-    FindPagedLODsVisitor(DatabasePager::PagedLODList& pagedLODList):
+    FindPagedLODsVisitor(DatabasePager::PagedLODList& pagedLODList, int frameNumber):
         osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
-        _pagedLODList(pagedLODList)
+        _activePagedLODList(pagedLODList),
+        _frameNumber(frameNumber)
     {
     }
     
     virtual void apply(osg::PagedLOD& plod)
     {
-        _pagedLODList.push_back(&plod);
+        plod.setFrameNumberOfLastTraversal(_frameNumber);
+        
+        _activePagedLODList.push_back(&plod);
     
         traverse(plod);
     }
     
-    DatabasePager::PagedLODList& _pagedLODList;
+    DatabasePager::PagedLODList& _activePagedLODList;
+    int _frameNumber;
 };
 
-void DatabasePager::registerPagedLODs(osg::Node* subgraph)
+void DatabasePager::registerPagedLODs(osg::Node* subgraph, int frameNumber)
 {
     if (!subgraph) return;
     
-    FindPagedLODsVisitor fplv(_pagedLODList);
+    FindPagedLODsVisitor fplv(_activePagedLODList, frameNumber);
     subgraph->accept(fplv);
 }
 
diff --git a/src/osgWrappers/osgDB/DatabasePager.cpp b/src/osgWrappers/osgDB/DatabasePager.cpp
index 8bb717f1b..ef0c78638 100644
--- a/src/osgWrappers/osgDB/DatabasePager.cpp
+++ b/src/osgWrappers/osgDB/DatabasePager.cpp
@@ -149,11 +149,11 @@ BEGIN_OBJECT_REFLECTOR(osgDB::DatabasePager)
 	          __void__signalEndFrame,
 	          "Signal the database thread that the update, cull and draw dispatch has completed. ",
 	          "Note, this is called by the application so that the database pager can go to wake back up now the main rendering threads are iddle waiting for the next frame. ");
-	I_Method1(void, registerPagedLODs, IN, osg::Node *, subgraph,
-	          Properties::VIRTUAL,
-	          __void__registerPagedLODs__osg_Node_P1,
-	          "Find all PagedLOD nodes in a subgraph and register them with the DatabasePager so it can keep track of expired nodes. ",
-	          "note, should be only be called from the update thread. ");
+	I_MethodWithDefaults2(void, registerPagedLODs, IN, osg::Node *, subgraph, , IN, int, frameNumber, 0,
+	                      Properties::VIRTUAL,
+	                      __void__registerPagedLODs__osg_Node_P1__int,
+	                      "Find all PagedLOD nodes in a subgraph and register them with the DatabasePager so it can keep track of expired nodes. ",
+	                      "note, should be only be called from the update thread. ");
 	I_Method1(void, setDoPreCompile, IN, bool, flag,
 	          Properties::NON_VIRTUAL,
 	          __void__setDoPreCompile__bool,
@@ -376,6 +376,18 @@ BEGIN_OBJECT_REFLECTOR(osgDB::DatabasePager)
 	                   __void__removeExpiredSubgraphs__C5_osg_FrameStamp_R1,
 	                   "Iterate through the active PagedLOD nodes children removing children which havn't been visited since specified expiryTime. ",
 	                   "note, should be only be called from the update thread. ");
+	I_ProtectedMethod1(void, expiry_removeExpiredSubgraphs, IN, const osg::FrameStamp &, frameStamp,
+	                   Properties::VIRTUAL,
+	                   Properties::NON_CONST,
+	                   __void__expiry_removeExpiredSubgraphs__C5_osg_FrameStamp_R1,
+	                   "Old expiry delay based removeExpiredSubgraphs. ",
+	                   "");
+	I_ProtectedMethod1(void, capped_removeExpiredSubgraphs, IN, const osg::FrameStamp &, frameStamp,
+	                   Properties::VIRTUAL,
+	                   Properties::NON_CONST,
+	                   __void__capped_removeExpiredSubgraphs__C5_osg_FrameStamp_R1,
+	                   "New capped based removeExpiredSubgraphs. ",
+	                   "");
 	I_ProtectedMethod1(void, addLoadedDataToSceneGraph, IN, const osg::FrameStamp &, frameStamp,
 	                   Properties::NON_VIRTUAL,
 	                   Properties::NON_CONST,