diff --git a/include/mapnik/pool.hpp b/include/mapnik/pool.hpp
index fe0572687..ba22cd7fa 100644
--- a/include/mapnik/pool.hpp
+++ b/include/mapnik/pool.hpp
@@ -42,28 +42,6 @@
 
 namespace mapnik
 {
-template <typename T, typename PoolT>
-class PoolGuard
-{
-private:
-    const T& obj_;
-    PoolT& pool_;
-public:
-    explicit PoolGuard(const T& ptr,PoolT& pool)
-        : obj_(ptr),
-          pool_(pool) {}
-
-    ~PoolGuard()
-    {
-        pool_->returnObject(obj_);
-    }
-
-private:
-    PoolGuard();
-    PoolGuard(const PoolGuard&);
-    PoolGuard& operator=(const PoolGuard&);
-};
-
 template <typename T,template <typename> class Creator>
 class Pool : private mapnik::noncopyable
 {
@@ -73,8 +51,7 @@ class Pool : private mapnik::noncopyable
     Creator<T> creator_;
     unsigned initialSize_;
     unsigned maxSize_;
-    ContType usedPool_;
-    ContType unusedPool_;
+    ContType pool_;
 #ifdef MAPNIK_THREADSAFE
     mutable boost::mutex mutex_;
 #endif
@@ -89,7 +66,7 @@ public:
         {
             HolderType conn(creator_());
             if (conn->isOK())
-                unusedPool_.push_back(conn);
+                pool_.push_back(conn);
         }
     }
 
@@ -98,31 +75,33 @@ public:
 #ifdef MAPNIK_THREADSAFE
         mutex::scoped_lock lock(mutex_);
 #endif
-        typename ContType::iterator itr=unusedPool_.begin();
-        while ( itr!=unusedPool_.end())
-        {
-            MAPNIK_LOG_DEBUG(pool) << "pool: Borrow instance=" << (*itr).get();
 
-            if ((*itr)->isOK())
+        typename ContType::iterator itr=pool_.begin();
+        while ( itr!=pool_.end())
+        {
+            if (!itr->unique())
             {
-                usedPool_.push_back(*itr);
-                unusedPool_.erase(itr);
-                return usedPool_.back();
+                ++itr;
+            }
+            else if ((*itr)->isOK())
+            {
+                MAPNIK_LOG_DEBUG(pool) << "pool: Borrow instance=" << (*itr).get();
+                return *itr;
             }
             else
             {
                 MAPNIK_LOG_DEBUG(pool) << "pool: Bad connection (erase) instance=" << (*itr).get();
 
-                itr=unusedPool_.erase(itr);
+                itr=pool_.erase(itr);
             }
         }
         // all connection have been taken, check if we allowed to grow pool
-        if (usedPool_.size() < maxSize_)
+        if (pool_.size() < maxSize_)
         {
             HolderType conn(creator_());
             if (conn->isOK())
             {
-                usedPool_.push_back(conn);
+                pool_.push_back(conn);
 
                 MAPNIK_LOG_DEBUG(pool) << "pool: Create connection=" << conn.get();
 
@@ -132,33 +111,12 @@ public:
         return HolderType();
     }
 
-    void returnObject(HolderType obj)
+    unsigned size() const
     {
 #ifdef MAPNIK_THREADSAFE
         mutex::scoped_lock lock(mutex_);
 #endif
-        typename ContType::iterator itr=usedPool_.begin();
-        while (itr != usedPool_.end())
-        {
-            if (obj.get()==(*itr).get())
-            {
-                MAPNIK_LOG_DEBUG(pool) << "pool: Return instance=" << (*itr).get();
-
-                unusedPool_.push_back(*itr);
-                usedPool_.erase(itr);
-                return;
-            }
-            ++itr;
-        }
-    }
-
-    std::pair<unsigned,unsigned> size() const
-    {
-#ifdef MAPNIK_THREADSAFE
-        mutex::scoped_lock lock(mutex_);
-#endif
-        std::pair<unsigned,unsigned> size(unusedPool_.size(),usedPool_.size());
-        return size;
+        return pool_.size();
     }
 
     unsigned max_size() const
@@ -193,7 +151,7 @@ public:
         if (size > initialSize_)
         {
             initialSize_ = size;
-            unsigned total_size = usedPool_.size() + unusedPool_.size();
+            unsigned total_size = pool_.size();
             // ensure we don't have ghost obj's in the pool.
             if (total_size < initialSize_)
             {
@@ -203,7 +161,7 @@ public:
                 {
                     HolderType conn(creator_());
                     if (conn->isOK())
-                        unusedPool_.push_back(conn);
+                        pool_.push_back(conn);
                 }
             }
         }
diff --git a/plugins/input/postgis/postgis_datasource.cpp b/plugins/input/postgis/postgis_datasource.cpp
index 394a036d1..586a3442d 100644
--- a/plugins/input/postgis/postgis_datasource.cpp
+++ b/plugins/input/postgis/postgis_datasource.cpp
@@ -53,7 +53,6 @@ const std::string postgis_datasource::GEOMETRY_COLUMNS = "geometry_columns";
 const std::string postgis_datasource::SPATIAL_REF_SYS = "spatial_ref_system";
 
 using boost::shared_ptr;
-using mapnik::PoolGuard;
 using mapnik::attribute_descriptor;
 
 postgis_datasource::postgis_datasource(parameters const& params)
@@ -115,8 +114,6 @@ postgis_datasource::postgis_datasource(parameters const& params)
         shared_ptr<Connection> conn = pool->borrowObject();
         if (!conn) return;
 
-        PoolGuard<shared_ptr<Connection>,
-                  shared_ptr< Pool<Connection,ConnectionCreator> > > guard(conn, pool);
         if (conn->isOK())
         {
 
@@ -431,7 +428,6 @@ postgis_datasource::~postgis_datasource()
             if (conn)
             {
                 conn->close();
-                pool->returnObject(conn);
             }
         }
     }
@@ -603,8 +599,6 @@ featureset_ptr postgis_datasource::features(const query& q) const
         shared_ptr<Connection> conn = pool->borrowObject();
         if (conn && conn->isOK())
         {
-            PoolGuard<shared_ptr<Connection>, shared_ptr< Pool<Connection,ConnectionCreator> > > guard(conn ,pool);
-
             if (geometryColumn_.empty())
             {
                 std::ostringstream s_error;
@@ -696,7 +690,6 @@ featureset_ptr postgis_datasource::features(const query& q) const
             if (conn)
             {
                 err_msg += conn->status();
-                pool->returnObject(conn);
             }
             else
             {
@@ -719,7 +712,6 @@ featureset_ptr postgis_datasource::features_at_point(coord2d const& pt, double t
     {
         shared_ptr<Connection> conn = pool->borrowObject();
         if (!conn) return featureset_ptr();
-        PoolGuard<shared_ptr<Connection>, shared_ptr< Pool<Connection,ConnectionCreator> > > guard(conn, pool);
 
         if (conn->isOK())
         {
@@ -804,7 +796,6 @@ box2d<double> postgis_datasource::envelope() const
     {
         shared_ptr<Connection> conn = pool->borrowObject();
         if (!conn) return extent_;
-        PoolGuard<shared_ptr<Connection>, shared_ptr< Pool<Connection,ConnectionCreator> > > guard(conn, pool);
         if (conn->isOK())
         {
             std::ostringstream s;
@@ -896,7 +887,6 @@ boost::optional<mapnik::datasource::geometry_t> postgis_datasource::get_geometry
     {
         shared_ptr<Connection> conn = pool->borrowObject();
         if (!conn) return result;
-        PoolGuard<shared_ptr<Connection>, shared_ptr< Pool<Connection,ConnectionCreator> > > guard(conn, pool);
         if (conn->isOK())
         {
             std::ostringstream s;