diff --git a/src/lib/datasrc/Makefile.am b/src/lib/datasrc/Makefile.am
index f4e768aafc..911d2f525c 100644
--- a/src/lib/datasrc/Makefile.am
+++ b/src/lib/datasrc/Makefile.am
@@ -31,7 +31,7 @@ libb10_datasrc_la_SOURCES += zonetable.h zonetable.cc
 libb10_datasrc_la_SOURCES += zone.h zone_finder.cc zone_finder_context.cc
 libb10_datasrc_la_SOURCES += result.h
 libb10_datasrc_la_SOURCES += logger.h logger.cc
-libb10_datasrc_la_SOURCES += client.h iterator.h
+libb10_datasrc_la_SOURCES += client.h client.cc iterator.h
 libb10_datasrc_la_SOURCES += database.h database.cc
 libb10_datasrc_la_SOURCES += factory.h factory.cc
 libb10_datasrc_la_SOURCES += client_list.h client_list.cc
diff --git a/src/lib/datasrc/client.cc b/src/lib/datasrc/client.cc
new file mode 100644
index 0000000000..e9db6bb072
--- /dev/null
+++ b/src/lib/datasrc/client.cc
@@ -0,0 +1,49 @@
+// Copyright (C) 2012  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <datasrc/client.h>
+
+#include <exceptions/exceptions.h>
+
+/// This file defines a few default implementations for methods.
+///
+/// While some of the detail of the API are worked out, we define
+/// default implementations to ease development for some of the
+/// more tentative methods (those that are not (yet) pure virtual)
+/// They should all throw NotImplemented
+
+namespace isc {
+namespace datasrc {
+
+ZoneIteratorPtr
+DataSourceClient::getIterator(const isc::dns::Name&, bool) const {
+    isc_throw(isc::NotImplemented,
+              "Data source doesn't support iteration");
+}
+
+unsigned int
+DataSourceClient::getZoneCount() const {
+    isc_throw(isc::NotImplemented,
+              "Data source doesn't support getZoneCount");
+}
+
+bool
+DataSourceClient::createZone(const dns::Name&) {
+    isc_throw(isc::NotImplemented,
+              "Data source doesn't support addZone");
+}
+
+
+} // end namespace datasrc
+} // end namespace isc
diff --git a/src/lib/datasrc/client.h b/src/lib/datasrc/client.h
index 33d1faa997..f65d87dd95 100644
--- a/src/lib/datasrc/client.h
+++ b/src/lib/datasrc/client.h
@@ -20,8 +20,6 @@
 #include <boost/noncopyable.hpp>
 #include <boost/shared_ptr.hpp>
 
-#include <exceptions/exceptions.h>
-
 #include <datasrc/zone.h>
 
 /// \file
@@ -225,15 +223,7 @@ public:
     ///                     adjusted to the lowest one found.
     /// \return Pointer to the iterator.
     virtual ZoneIteratorPtr getIterator(const isc::dns::Name& name,
-                                        bool separate_rrs = false) const {
-        // This is here to both document the parameter in doxygen (therefore it
-        // needs a name) and avoid unused parameter warning.
-        static_cast<void>(name);
-        static_cast<void>(separate_rrs);
-
-        isc_throw(isc::NotImplemented,
-                  "Data source doesn't support iteration");
-    }
+                                        bool separate_rrs = false) const;
 
     /// Return an updater to make updates to a specific zone.
     ///
@@ -368,16 +358,15 @@ public:
     /// This is an optional convenience method, currently only implemented
     /// by the InMemory datasource. By default, it throws NotImplemented
     ///
+    /// \note This is a tentative API, and this method is likely to change
+    /// or be removed in the near future. For that reason, it currently
+    /// provides a default implementation that throws NotImplemented.
+    ///
     /// \exception NotImplemented Thrown if this method is not supported
     ///            by the datasource
     ///
-    /// \note This is a tentative API, and this method may likely to be
-    ///       removed in the near future.
     /// \return The number of zones known to this datasource
-    virtual unsigned int getZoneCount() const {
-        isc_throw(isc::NotImplemented,
-                  "Data source doesn't support getZoneCount");
-    }
+    virtual unsigned int getZoneCount() const;
 
     /// \brief Create a zone in the database
     ///
@@ -385,7 +374,8 @@ public:
     /// can subsequently be filled with data (through getUpdater()).
     ///
     /// \note This is a tentative API, and this method is likely to change
-    /// or be removed in the near future.
+    /// or be removed in the near future. For that reason, it currently
+    /// provides a default implementation that throws NotImplemented.
     ///
     /// Apart from the two exceptions mentioned below, in theory this
     /// call can throw anything, depending on the implementation of
@@ -397,10 +387,7 @@ public:
     ///                        while creating the zone.
     /// \param name The (fully qualified) name of the zone to create
     /// \return True if the zone was added, false if it already existed
-    virtual bool createZone(const dns::Name&) {
-        isc_throw(isc::NotImplemented,
-                  "Data source doesn't support addZone");
-    }
+    virtual bool createZone(const dns::Name& name);
 };
 }
 }