diff --git a/UnitTests/HttpInterface/api-collection_spec.rb b/UnitTests/HttpInterface/api-collection_spec.rb
index e656c0292c..a4ffaa77c0 100644
--- a/UnitTests/HttpInterface/api-collection_spec.rb
+++ b/UnitTests/HttpInterface/api-collection_spec.rb
@@ -30,9 +30,9 @@ describe AvocadoDB do
         doc = AvocadoDB.log_get("#{prefix}-all-collections", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
-	doc.headers['content-type'].should eq("application/json")
 
 	collections = doc.parsed_response['collections']
 	names = doc.parsed_response['names']
@@ -53,10 +53,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_get("#{prefix}-bad-handle", cmd)
 
 	doc.code.should eq(404)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(true)
 	doc.parsed_response['errorNum'].should eq(1203)
 	doc.parsed_response['code'].should eq(404)
-	doc.headers['content-type'].should eq("application/json")
       end
 
       it "creating a collection without name" do
@@ -64,10 +64,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-missing-name", cmd)
 
 	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(true)
 	doc.parsed_response['code'].should eq(400)
 	doc.parsed_response['errorNum'].should eq(1208)
-	doc.headers['content-type'].should eq("application/json")
       end
 
       it "creating a collection with an illegal name" do
@@ -76,10 +76,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-illegal-name", cmd, :body => body)
 
 	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(true)
 	doc.parsed_response['code'].should eq(400)
 	doc.parsed_response['errorNum'].should eq(1208)
-	doc.headers['content-type'].should eq("application/json")
       end
 
       it "creating a collection with a duplicate name" do
@@ -91,10 +91,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-illegal-name", cmd, :body => body)
 
 	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(true)
 	doc.parsed_response['code'].should eq(400)
 	doc.parsed_response['errorNum'].should eq(1207)
-	doc.headers['content-type'].should eq("application/json")
       end
 
       it "creating a collection with an illegal body" do
@@ -103,11 +103,11 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-illegal-body", cmd, :body => body)
 
 	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(true)
 	doc.parsed_response['code'].should eq(400)
 	doc.parsed_response['errorNum'].should eq(600)
 	doc.parsed_response['errorMessage'].should eq("SyntaxError: Unexpected token n")
-	doc.headers['content-type'].should eq("application/json")
       end
 
       it "creating a collection with a null body" do
@@ -116,10 +116,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-null-body", cmd, :body => body)
 
 	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(true)
 	doc.parsed_response['code'].should eq(400)
 	doc.parsed_response['errorNum'].should eq(1208)
-	doc.headers['content-type'].should eq("application/json")
       end
     end
 
@@ -143,10 +143,9 @@ describe AvocadoDB do
         doc = AvocadoDB.log_get("#{prefix}-get-collection-identifier", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
-	doc.headers['content-type'].should eq("application/json")
-
 	doc.parsed_response['id'].should eq(@cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should be_kind_of(Integer)
@@ -158,10 +157,9 @@ describe AvocadoDB do
         doc = AvocadoDB.log_get("#{prefix}-get-collection-name", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
-	doc.headers['content-type'].should eq("application/json")
-
 	doc.parsed_response['id'].should eq(@cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should be_kind_of(Integer)
@@ -173,10 +171,9 @@ describe AvocadoDB do
         doc = AvocadoDB.log_get("#{prefix}-get-collection-count", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
-	doc.headers['content-type'].should eq("application/json")
-
 	doc.parsed_response['id'].should eq(@cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should eq(3)
@@ -189,10 +186,9 @@ describe AvocadoDB do
         doc = AvocadoDB.log_get("#{prefix}-get-collection-figures", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
-	doc.headers['content-type'].should eq("application/json")
-
 	doc.parsed_response['id'].should eq(@cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should eq(3)
@@ -219,10 +215,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_delete("#{prefix}-delete-collection-identifier", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should eq(cid)
-	doc.headers['content-type'].should eq("application/json")
 
 	cmd = api + "/" + String(cid)
 	doc = AvocadoDB.get(cmd)
@@ -237,10 +233,10 @@ describe AvocadoDB do
         doc = AvocadoDB.log_delete("#{prefix}-delete-collection-name", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should eq(cid)
-	doc.headers['content-type'].should eq("application/json")
 
 	cmd = api + "/" + String(cid)
 	doc = AvocadoDB.get(cmd)
@@ -265,12 +261,12 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-collection", cmd, :body => body)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should be_kind_of(Integer)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['waitForSync'].should == false
-	doc.headers['content-type'].should eq("application/json")
 
 	cmd = api + "/" + String(@cn) + "/figures"
         doc = AvocadoDB.get(cmd)
@@ -286,12 +282,12 @@ describe AvocadoDB do
         doc = AvocadoDB.log_post("#{prefix}-create-collection-sync", cmd, :body => body)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should be_kind_of(Integer)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['waitForSync'].should == true
-	doc.headers['content-type'].should eq("application/json")
 
 	cmd = api + "/" + String(@cn) + "/figures"
         doc = AvocadoDB.get(cmd)
@@ -303,10 +299,10 @@ describe AvocadoDB do
     end
 
 ################################################################################
-## updating a collection
+## load a collection
 ################################################################################
 
-    context "updating:" do
+    context "loading:" do
       before do
 	@cn = "UnitTestsCollectionBasics"
       end
@@ -319,13 +315,13 @@ describe AvocadoDB do
         doc = AvocadoDB.log_put("#{prefix}-identifier-load", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should eq(cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should eq(3)
 	doc.parsed_response['count'].should be_kind_of(Integer)
-	doc.headers['content-type'].should eq("application/json")
 
 	AvocadoDB.drop_collection(@cn)
       end
@@ -338,16 +334,26 @@ describe AvocadoDB do
         doc = AvocadoDB.log_put("#{prefix}-name-load", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should eq(cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should eq(3)
 	doc.parsed_response['count'].should be_kind_of(Integer)
-	doc.headers['content-type'].should eq("application/json")
 
 	AvocadoDB.drop_collection(@cn)
       end
+    end
+
+################################################################################
+## unloading a collection
+################################################################################
+
+    context "unloading:" do
+      before do
+	@cn = "UnitTestsCollectionBasics"
+      end
 
       it "unload a collection by identifier" do
 	AvocadoDB.drop_collection(@cn)
@@ -357,12 +363,12 @@ describe AvocadoDB do
         doc = AvocadoDB.log_put("#{prefix}-identifier-unload", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should eq(cid)
 	doc.parsed_response['name'].should eq(@cn)
 	doc.parsed_response['status'].should eq(4)
-	doc.headers['content-type'].should eq("application/json")
 
 	AvocadoDB.drop_collection(@cn)
       end
@@ -375,16 +381,278 @@ describe AvocadoDB do
         doc = AvocadoDB.log_put("#{prefix}-name-unload", cmd)
 
 	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
 	doc.parsed_response['error'].should eq(false)
 	doc.parsed_response['code'].should eq(200)
 	doc.parsed_response['id'].should eq(cid)
 	doc.parsed_response['name'].should eq(@cn)
 	[2,4].include?(doc.parsed_response['status']).should be_true
-	doc.headers['content-type'].should eq("application/json")
 
 	AvocadoDB.drop_collection(@cn)
       end
     end
 
+################################################################################
+## truncate a collection
+################################################################################
+
+    context "truncating:" do
+      before do
+	@cn = "UnitTestsCollectionBasics"
+	@cid = AvocadoDB.create_collection(@cn)
+      end
+
+      after do
+	AvocadoDB.drop_collection(@cn)
+      end
+
+      it "truncate a collection by identifier" do
+	cmd = "/document?collection=#{@cid}"
+	body = "{ \"Hallo\" : \"World\" }"
+
+	for i in ( 1 .. 10 )
+	  doc = AvocadoDB.post(cmd, :body => body)
+	end
+
+	AvocadoDB.size_collection(@cid).should eq(10)
+
+	cmd = api + "/" + String(@cid) + "/truncate"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-truncate", cmd)
+
+	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['code'].should eq(200)
+	doc.parsed_response['id'].should eq(@cid)
+	doc.parsed_response['name'].should eq(@cn)
+	doc.parsed_response['status'].should eq(3)
+
+	AvocadoDB.size_collection(@cid).should eq(0)
+
+	AvocadoDB.drop_collection(@cn)
+      end
+    end
+
+################################################################################
+## renames a collection
+################################################################################
+
+    context "renaming:" do
+      it "rename a collection by identifier" do
+	cn = "UnitTestsCollectionBasics"
+	AvocadoDB.drop_collection(cn)
+	cid = AvocadoDB.create_collection(cn)
+
+	cmd = "/document?collection=#{cid}"
+	body = "{ \"Hallo\" : \"World\" }"
+
+	for i in ( 1 .. 10 )
+	  doc = AvocadoDB.post(cmd, :body => body)
+	end
+
+	AvocadoDB.size_collection(cid).should eq(10)
+	AvocadoDB.size_collection(cn).should eq(10)
+
+	cn2 = "UnitTestsCollectionBasics2"
+	AvocadoDB.drop_collection(cn2)
+
+	body = "{ \"name\" : \"#{cn2}\" }"
+	cmd = api + "/" + String(cid) + "/rename"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-rename", cmd, :body => body)
+
+	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['code'].should eq(200)
+	doc.parsed_response['id'].should eq(cid)
+	doc.parsed_response['name'].should eq(cn2)
+	doc.parsed_response['status'].should eq(3)
+
+	AvocadoDB.size_collection(cid).should eq(10)
+	AvocadoDB.size_collection(cn2).should eq(10)
+
+	cmd = api + "/" + String(cn)
+        doc = AvocadoDB.get(cmd)
+
+	doc.code.should eq(404)
+	doc.parsed_response['error'].should eq(true)
+	doc.parsed_response['errorNum'].should eq(1203)
+
+	cmd = api + "/" + String(cn2)
+        doc = AvocadoDB.get(cmd)
+
+	doc.code.should eq(200)
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['name'].should eq(cn2)
+	doc.parsed_response['status'].should eq(3)
+
+	AvocadoDB.drop_collection(cn)
+	AvocadoDB.drop_collection(cn2)
+      end
+
+      it "rename a collection by identifier with conflict" do
+	cn = "UnitTestsCollectionBasics"
+	AvocadoDB.drop_collection(cn)
+	cid = AvocadoDB.create_collection(cn)
+
+	cn2 = "UnitTestsCollectionBasics2"
+	AvocadoDB.drop_collection(cn2)
+	cid2 = AvocadoDB.create_collection(cn2)
+
+	body = "{ \"Hallo\" : \"World\" }"
+
+	cmd = "/document?collection=#{cid}"
+
+	for i in ( 1 .. 10 )
+	  doc = AvocadoDB.post(cmd, :body => body)
+	end
+
+	AvocadoDB.size_collection(cid).should eq(10)
+	AvocadoDB.size_collection(cn).should eq(10)
+
+	cmd = "/document?collection=#{cid2}"
+
+	for i in ( 1 .. 20 )
+	  doc = AvocadoDB.post(cmd, :body => body)
+	end
+
+	AvocadoDB.size_collection(cid2).should eq(20)
+	AvocadoDB.size_collection(cn2).should eq(20)
+
+	body = "{ \"name\" : \"#{cn2}\" }"
+	cmd = api + "/" + String(cid) + "/rename"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-rename-conflict", cmd, :body => body)
+
+	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(true)
+	doc.parsed_response['code'].should eq(400)
+	doc.parsed_response['errorNum'].should eq(1207)
+
+	AvocadoDB.size_collection(cid).should eq(10)
+	AvocadoDB.size_collection(cn).should eq(10)
+
+	AvocadoDB.size_collection(cid2).should eq(20)
+	AvocadoDB.size_collection(cn2).should eq(20)
+
+	AvocadoDB.drop_collection(cn)
+	AvocadoDB.drop_collection(cn2)
+      end
+
+      it "rename a new-born collection by identifier" do
+	cn = "UnitTestsCollectionBasics"
+	AvocadoDB.drop_collection(cn)
+	cid = AvocadoDB.create_collection(cn)
+
+	cn2 = "UnitTestsCollectionBasics2"
+	AvocadoDB.drop_collection(cn2)
+
+	body = "{ \"name\" : \"#{cn2}\" }"
+	cmd = api + "/" + String(cid) + "/rename"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-rename-new-born", cmd, :body => body)
+
+	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['code'].should eq(200)
+	doc.parsed_response['id'].should eq(cid)
+	doc.parsed_response['name'].should eq(cn2)
+	doc.parsed_response['status'].should eq(3)
+
+	cmd = api + "/" + String(cn)
+        doc = AvocadoDB.get(cmd)
+
+	doc.code.should eq(404)
+	doc.parsed_response['error'].should eq(true)
+	doc.parsed_response['errorNum'].should eq(1203)
+
+	cmd = api + "/" + String(cn2)
+        doc = AvocadoDB.get(cmd)
+
+	doc.code.should eq(200)
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['name'].should eq(cn2)
+	doc.parsed_response['status'].should eq(3)
+
+	AvocadoDB.drop_collection(cn)
+	AvocadoDB.drop_collection(cn2)
+      end
+
+      it "rename a new-born collection by identifier with conflict" do
+	cn = "UnitTestsCollectionBasics"
+	AvocadoDB.drop_collection(cn)
+	cid = AvocadoDB.create_collection(cn)
+
+	cn2 = "UnitTestsCollectionBasics2"
+	AvocadoDB.drop_collection(cn2)
+	cid2 = AvocadoDB.create_collection(cn2)
+
+	cmd = "/document?collection=#{cid2}"
+
+	body = "{ \"name\" : \"#{cn2}\" }"
+	cmd = api + "/" + String(cid) + "/rename"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-rename-conflict", cmd, :body => body)
+
+	doc.code.should eq(400)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(true)
+	doc.parsed_response['code'].should eq(400)
+	doc.parsed_response['errorNum'].should eq(1207)
+
+	AvocadoDB.drop_collection(cn)
+	AvocadoDB.drop_collection(cn2)
+      end
+    end
+
+################################################################################
+## parameter a collection
+################################################################################
+
+    context "parameter:" do
+      it "changing the parameter of a collection by identifier" do
+	cn = "UnitTestsCollectionBasics"
+	AvocadoDB.drop_collection(cn)
+	cid = AvocadoDB.create_collection(cn)
+
+	cmd = "/document?collection=#{cid}"
+	body = "{ \"Hallo\" : \"World\" }"
+
+	for i in ( 1 .. 10 )
+	  doc = AvocadoDB.post(cmd, :body => body)
+	end
+
+	AvocadoDB.size_collection(cid).should eq(10)
+	AvocadoDB.size_collection(cn).should eq(10)
+
+	cmd = api + "/" + String(cid) + "/parameter"
+	body = "{ \"waitForSync\" : true }"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-parameter-sync", cmd, :body => body)
+
+	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['code'].should eq(200)
+	doc.parsed_response['id'].should eq(cid)
+	doc.parsed_response['name'].should eq(cn)
+	doc.parsed_response['status'].should eq(3)
+	doc.parsed_response['waitForSync'].should eq(true)
+
+	cmd = api + "/" + String(cid) + "/parameter"
+	body = "{ \"waitForSync\" : false }"
+        doc = AvocadoDB.log_put("#{prefix}-identifier-parameter-no-sync", cmd, :body => body)
+
+	doc.code.should eq(200)
+	doc.headers['content-type'].should eq("application/json")
+	doc.parsed_response['error'].should eq(false)
+	doc.parsed_response['code'].should eq(200)
+	doc.parsed_response['id'].should eq(cid)
+	doc.parsed_response['name'].should eq(cn)
+	doc.parsed_response['status'].should eq(3)
+	doc.parsed_response['waitForSync'].should eq(false)
+
+	AvocadoDB.drop_collection(cn)
+      end
+    end
+
   end
 end
diff --git a/V8/v8-vocbase.cpp b/V8/v8-vocbase.cpp
index 4be37f70e6..e601c84521 100644
--- a/V8/v8-vocbase.cpp
+++ b/V8/v8-vocbase.cpp
@@ -3162,23 +3162,19 @@ static v8::Handle<v8::Value> JS_DeleteVocbaseCol (v8::Arguments const& argv) {
   // inside a write transaction
   // .............................................................................
 
-  bool ok = doc->destroyLock(doc, did, 0, 0, TRI_DOC_UPDATE_LAST_WRITE);
+  int res = doc->destroyLock(doc, did, 0, 0, TRI_DOC_UPDATE_LAST_WRITE);
 
   // .............................................................................
   // outside a write transaction
   // .............................................................................
 
-  if (! ok) {
-    if (TRI_errno() == TRI_ERROR_AVOCADO_DOCUMENT_NOT_FOUND) {
+  if (res != TRI_ERROR_NO_ERROR) {
+    if (res == TRI_ERROR_AVOCADO_DOCUMENT_NOT_FOUND) {
       ReleaseCollection(collection);
       return scope.Close(v8::False());
     }
     else {
-      string err = "cannot delete document: ";
-      err += TRI_last_error();
-
-      ReleaseCollection(collection);
-      return scope.Close(v8::ThrowException(v8::String::New(err.c_str())));
+      return scope.Close(v8::ThrowException(CreateErrorObject(res, "cannot delete document")));
     }
   }
 
@@ -4301,10 +4297,7 @@ static v8::Handle<v8::Value> JS_RenameVocbaseCol (v8::Arguments const& argv) {
   int res = TRI_RenameCollectionVocBase(collection->_vocbase, collection, name.c_str());
 
   if (res != TRI_ERROR_NO_ERROR) {
-    string err = "cannot rename collection: ";
-    err += TRI_last_error();
-
-    return scope.Close(v8::ThrowException(v8::String::New(err.c_str())));
+    return scope.Close(v8::ThrowException(CreateErrorObject(res, "cannot rename collection")));
   }
 
   return scope.Close(v8::Undefined());
diff --git a/VocBase/blob-collection.c b/VocBase/blob-collection.c
index 3ec35793a1..009da6e48a 100644
--- a/VocBase/blob-collection.c
+++ b/VocBase/blob-collection.c
@@ -315,7 +315,6 @@ TRI_blob_collection_t* TRI_CreateBlobCollection (char const* path, TRI_col_param
   info._cid = TRI_NewTickVocBase();
   TRI_CopyString(info._name, parameter->_name, sizeof(info._name));
   info._maximalSize = parameter->_maximalSize;
-  info._size = sizeof(TRI_col_info_t);
 
   collection = TRI_CreateCollection(&blob->base, path, &info);
 
diff --git a/VocBase/collection.c b/VocBase/collection.c
index fd2cd6e4f3..221e7f1380 100644
--- a/VocBase/collection.c
+++ b/VocBase/collection.c
@@ -647,7 +647,6 @@ int TRI_UpdateParameterInfoCollection (TRI_collection_t* collection) {
   parameter._maximalSize = collection->_maximalSize;
   parameter._waitForSync = collection->_waitForSync;
   parameter._deleted = collection->_deleted;
-  parameter._size = sizeof(TRI_col_info_t);
 
   return TRI_SaveParameterInfoCollection(collection->_directory, &parameter);
 }
@@ -670,7 +669,6 @@ int TRI_RenameCollection (TRI_collection_t* collection, char const* name) {
   parameter._maximalSize = collection->_maximalSize;
   parameter._waitForSync = collection->_waitForSync;
   parameter._deleted = collection->_deleted;
-  parameter._size = sizeof(TRI_col_info_t);
 
   res = TRI_SaveParameterInfoCollection(collection->_directory, &parameter);
 
diff --git a/VocBase/collection.h b/VocBase/collection.h
index fa51214dc1..5f34bcec19 100644
--- a/VocBase/collection.h
+++ b/VocBase/collection.h
@@ -179,8 +179,6 @@ typedef struct TRI_col_info_s {
   bool _waitForSync;                 // if true, wait for msync
 
   bool _deleted;                     // if true, collections has been deleted
-
-  TRI_voc_size_t _size;              // total size of the parameter info block
 }
 TRI_col_info_t;
 
diff --git a/VocBase/simple-collection.c b/VocBase/simple-collection.c
index 7ecf54a263..1756f509eb 100644
--- a/VocBase/simple-collection.c
+++ b/VocBase/simple-collection.c
@@ -1786,7 +1786,6 @@ TRI_sim_collection_t* TRI_CreateSimCollection (char const* path,
   TRI_CopyString(info._name, parameter->_name, sizeof(info._name));
   info._waitForSync = parameter->_waitForSync;
   info._maximalSize = parameter->_maximalSize;
-  info._size = sizeof(TRI_col_info_t);
 
   // first create the document collection
   doc = TRI_Allocate(sizeof(TRI_sim_collection_t));
diff --git a/VocBase/vocbase.c b/VocBase/vocbase.c
index 853697900a..37e411afd1 100644
--- a/VocBase/vocbase.c
+++ b/VocBase/vocbase.c
@@ -1506,8 +1506,7 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
   }
 
   // check if the new name is unused
-  cnv.c = collection;
-  found = TRI_InsertKeyAssociativePointer(&vocbase->_collectionsByName, newName, cnv.v, false);
+  found = TRI_LookupByKeyAssociativePointer(&vocbase->_collectionsByName, newName);
 
   if (found != NULL) {
     TRI_WRITE_UNLOCK_COLLECTIONS_VOCBASE(vocbase);
@@ -1521,7 +1520,7 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
   // .............................................................................
 
   if (collection->_status == TRI_VOC_COL_STATUS_NEW_BORN) {
-    TRI_CopyString(collection->_name, newName, sizeof(collection->_name));
+    // do nothing
   }
 
   // .............................................................................
@@ -1532,8 +1531,6 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
     res = TRI_LoadParameterInfoCollection(collection->_path, &info);
 
     if (res != TRI_ERROR_NO_ERROR) {
-      TRI_RemoveKeyAssociativePointer(&vocbase->_collectionsByName, newName);
-
       TRI_WRITE_UNLOCK_COLLECTIONS_VOCBASE(vocbase);
       TRI_WRITE_UNLOCK_STATUS_VOCBASE_COL(collection);
 
@@ -1545,15 +1542,11 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
     res = TRI_SaveParameterInfoCollection(collection->_path, &info);
 
     if (res != TRI_ERROR_NO_ERROR) {
-      TRI_RemoveKeyAssociativePointer(&vocbase->_collectionsByName, newName);
-
       TRI_WRITE_UNLOCK_COLLECTIONS_VOCBASE(vocbase);
       TRI_WRITE_UNLOCK_STATUS_VOCBASE_COL(collection);
 
       return TRI_set_errno(res);
     }
-
-    TRI_CopyString(collection->_name, newName, sizeof(collection->_name));
   }
 
   // .............................................................................
@@ -1564,15 +1557,11 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
     res = TRI_RenameCollection(&collection->_collection->base, newName);
 
     if (res != TRI_ERROR_NO_ERROR) {
-      TRI_RemoveKeyAssociativePointer(&vocbase->_collectionsByName, newName);
-
       TRI_WRITE_UNLOCK_COLLECTIONS_VOCBASE(vocbase);
       TRI_WRITE_UNLOCK_STATUS_VOCBASE_COL(collection);
 
       return TRI_set_errno(res);
     }
-
-    TRI_CopyString(collection->_name, newName, sizeof(collection->_name));
   }
 
   // .............................................................................
@@ -1580,8 +1569,6 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
   // .............................................................................
 
   else {
-    TRI_RemoveKeyAssociativePointer(&vocbase->_collectionsByName, newName);
-
     TRI_WRITE_UNLOCK_COLLECTIONS_VOCBASE(vocbase);
     TRI_WRITE_UNLOCK_STATUS_VOCBASE_COL(collection);
 
@@ -1589,10 +1576,14 @@ int TRI_RenameCollectionVocBase (TRI_vocbase_t* vocbase, TRI_vocbase_col_t* coll
   }
   
   // .............................................................................
-  // remove old name and release locks
+  // rename and release locks
   // .............................................................................
 
   TRI_RemoveKeyAssociativePointer(&vocbase->_collectionsByName, oldName);
+  TRI_CopyString(collection->_name, newName, sizeof(collection->_name));
+
+  cnv.c = collection;
+  TRI_InsertKeyAssociativePointer(&vocbase->_collectionsByName, newName, cnv.v, false);
 
   TRI_WRITE_UNLOCK_COLLECTIONS_VOCBASE(vocbase);
   TRI_WRITE_UNLOCK_STATUS_VOCBASE_COL(collection);
diff --git a/js/actions/system/api-collection.js b/js/actions/system/api-collection.js
index bb3e00f2f5..f3b8a7e220 100644
--- a/js/actions/system/api-collection.js
+++ b/js/actions/system/api-collection.js
@@ -100,7 +100,6 @@ function CollectionRepresentation (collection, showParameter, showCount, showFig
 /// @brief creates a collection
 ///
 /// @REST{POST /_api/collection}
-////////////////////////////////
 ///
 /// Creates an new collection with a given name. The request must contain an
 /// object with the following attributes.
@@ -112,7 +111,6 @@ function CollectionRepresentation (collection, showParameter, showCount, showFig
 /// document.
 ///
 /// @EXAMPLES
-/////////////
 ///
 /// @verbinclude api-collection-create-collection
 ////////////////////////////////////////////////////////////////////////////////
@@ -128,8 +126,6 @@ function POST_api_collection (req, res) {
     return;
   }
 
-  var waitForSync = false;
-
   if (! body.hasOwnProperty("name")) {
     actions.resultBad(req, res, actions.ERROR_AVOCADO_ILLEGAL_NAME,
                       "name must be non-empty");
@@ -137,6 +133,7 @@ function POST_api_collection (req, res) {
   }
 
   var name = body.name;
+  var waitForSync = false;
 
   if (body.hasOwnProperty("waitForSync")) {
     waitForSync = body.waitForSync;
@@ -166,7 +163,6 @@ function POST_api_collection (req, res) {
 /// @brief returns all collections
 ///
 /// @REST{GET /_api/collection}
-///////////////////////////////
 ///
 /// Returns an object with an attribute @LIT{collections} containing a 
 /// list of all collection descriptions. The same information is also
@@ -174,7 +170,6 @@ function POST_api_collection (req, res) {
 /// as keys.
 ///
 /// @EXAMPLES
-/////////////
 ///
 /// Return information about all collections:
 ///
@@ -353,7 +348,6 @@ function GET_api_collection (req, res) {
 /// @brief loads a collection
 ///
 /// @REST{PUT /_api/collection/@FA{collection-identifier}/load}
-///////////////////////////////////////////////////////////////
 ///
 /// Loads a collection into memory.  On success an object with the following
 ///
@@ -372,7 +366,6 @@ function GET_api_collection (req, res) {
 /// It is possible to specify a name instead of an identifier.
 ///
 /// @EXAMPLES
-/////////////
 ///
 /// @verbinclude api-collection-identifier-load
 ////////////////////////////////////////////////////////////////////////////////
@@ -394,7 +387,6 @@ function PUT_api_collection_load (req, res, collection) {
 /// @brief unloads a collection
 ///
 /// @REST{PUT /_api/collection/@FA{collection-identifier}/unload}
-/////////////////////////////////////////////////////////////////
 ///
 /// Removes a collection from memory. This call does not delete any documents.
 /// You can use the collection afterwards; in which case it will be loaded into
@@ -411,7 +403,6 @@ function PUT_api_collection_load (req, res, collection) {
 /// 404} is returned.
 ///
 /// @EXAMPLES
-/////////////
 ///
 /// @verbinclude api-collection-identifier-unload
 ////////////////////////////////////////////////////////////////////////////////
@@ -433,23 +424,31 @@ function PUT_api_collection_unload (req, res, collection) {
 /// @brief truncates a collection
 ///
 /// @REST{PUT /_api/collection/@FA{collection-identifier}/truncate}
-///////////////////////////////////////////////////////////////////
 ///
 /// Removes all documents from the collection, but leaves the indexes intact.
 ///
 /// @EXAMPLES
-/////////////
 ///
+/// @verbinclude api-collection-identifier-truncate
 ////////////////////////////////////////////////////////////////////////////////
 
 function PUT_api_collection_truncate (req, res, collection) {
+  try {
+    collection.truncate();
+
+    var result = CollectionRepresentation(collection);
+    
+    actions.resultOk(req, res, actions.HTTP_OK, result);
+  }
+  catch (err) {
+    actions.resultException(req, res, err);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief changes a collection
 ///
 /// @REST{PUT /_api/collection/@FA{collection-identifier}/parameter}
-////////////////////////////////////////////////////////////////////
 ///
 /// Changes the parameter of a collection. Expects an object with the
 /// attribute(s)
@@ -466,18 +465,36 @@ function PUT_api_collection_truncate (req, res, collection) {
 /// @LIT{waitForSync}: The new value.
 ///
 /// @EXAMPLES
-/////////////
 ///
 ////////////////////////////////////////////////////////////////////////////////
 
 function PUT_api_collection_parameter (req, res, collection) {
+  var body;
+
+  try {
+    body = JSON.parse(req.requestBody || "{}") || {};
+  }
+  catch (err) {
+    actions.resultBad(req, res, actions.ERROR_HTTP_CORRUPTED_JSON, err);
+    return;
+  }
+
+  try {
+    collection.parameter(body);
+
+    var result = CollectionRepresentation(collection, true);
+    
+    actions.resultOk(req, res, actions.HTTP_OK, result);
+  }
+  catch (err) {
+    actions.resultException(req, res, err);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief renames a collection
 ///
 /// @REST{PUT /_api/collection/@FA{collection-identifier}/rename}
-/////////////////////////////////////////////////////////////////
 ///
 /// Renames a collection. Expects an object with the attribute(s)
 ///
@@ -490,11 +507,39 @@ function PUT_api_collection_parameter (req, res, collection) {
 /// @LIT{name}: The new name of the collection.
 ///
 /// @EXAMPLES
-/////////////
 ///
+/// @verbinclude api-collection-identifier-rename
 ////////////////////////////////////////////////////////////////////////////////
 
 function PUT_api_collection_rename (req, res, collection) {
+  var body;
+
+  try {
+    body = JSON.parse(req.requestBody || "{}") || {};
+  }
+  catch (err) {
+    actions.resultBad(req, res, actions.ERROR_HTTP_CORRUPTED_JSON, err);
+    return;
+  }
+
+  if (! body.hasOwnProperty("name")) {
+    actions.resultBad(req, res, actions.ERROR_AVOCADO_ILLEGAL_NAME,
+                      "name must be non-empty");
+    return;
+  }
+
+  var name = body.name;
+
+  try {
+    collection.rename(name);
+
+    var result = CollectionRepresentation(collection);
+    
+    actions.resultOk(req, res, actions.HTTP_OK, result);
+  }
+  catch (err) {
+    actions.resultException(req, res, err);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/js/server/js-server.h b/js/server/js-server.h
index b9c52525f2..d27534bf1b 100644
--- a/js/server/js-server.h
+++ b/js/server/js-server.h
@@ -168,6 +168,30 @@ static string JS_server_server =
   "AvocadoEdges.prototype._drop = AvocadoDatabase._drop;\n"
   "\n"
   "////////////////////////////////////////////////////////////////////////////////\n"
+  "/// @brief truncates a collection\n"
+  "////////////////////////////////////////////////////////////////////////////////\n"
+  "\n"
+  "AvocadoDatabase.prototype._truncate = function(name) {\n"
+  "  var collection = name;\n"
+  "\n"
+  "  if (typeof name === \"string\") {\n"
+  "    collection = db[name];\n"
+  "  }\n"
+  "\n"
+  "  if (collection == null) {\n"
+  "    return;\n"
+  "  }\n"
+  "\n"
+  "  var all = collection.ALL(null, null).documents;\n"
+  "\n"
+  "  for (var i = 0;  i < all.length;  ++i) {\n"
+  "    collection.delete(all[i]._id);\n"
+  "  }\n"
+  "}\n"
+  "\n"
+  "AvocadoEdges.prototype._truncate = AvocadoDatabase._truncate;\n"
+  "\n"
+  "////////////////////////////////////////////////////////////////////////////////\n"
   "/// @}\n"
   "////////////////////////////////////////////////////////////////////////////////\n"
   "\n"
@@ -225,6 +249,14 @@ static string JS_server_server =
   "}\n"
   "\n"
   "////////////////////////////////////////////////////////////////////////////////\n"
+  "/// @brief truncates a collection\n"
+  "////////////////////////////////////////////////////////////////////////////////\n"
+  "\n"
+  "AvocadoCollection.prototype.truncate = function() {\n"
+  "  return db._truncate(this);\n"
+  "}\n"
+  "\n"
+  "////////////////////////////////////////////////////////////////////////////////\n"
   "/// @brief prints a collection\n"
   "////////////////////////////////////////////////////////////////////////////////\n"
   "\n"
diff --git a/js/server/server.js b/js/server/server.js
index f177311259..94c4449b3d 100644
--- a/js/server/server.js
+++ b/js/server/server.js
@@ -166,6 +166,30 @@ AvocadoDatabase.prototype._drop = function(name) {
 
 AvocadoEdges.prototype._drop = AvocadoDatabase._drop;
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief truncates a collection
+////////////////////////////////////////////////////////////////////////////////
+
+AvocadoDatabase.prototype._truncate = function(name) {
+  var collection = name;
+
+  if (typeof name === "string") {
+    collection = db[name];
+  }
+
+  if (collection == null) {
+    return;
+  }
+
+  var all = collection.ALL(null, null).documents;
+
+  for (var i = 0;  i < all.length;  ++i) {
+    collection.delete(all[i]._id);
+  }
+}
+
+AvocadoEdges.prototype._truncate = AvocadoDatabase._truncate;
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @}
 ////////////////////////////////////////////////////////////////////////////////
@@ -223,6 +247,14 @@ AvocadoCollection.prototype.toArray = function() {
   return this.all().toArray();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief truncates a collection
+////////////////////////////////////////////////////////////////////////////////
+
+AvocadoCollection.prototype.truncate = function() {
+  return db._truncate(this);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief prints a collection
 ////////////////////////////////////////////////////////////////////////////////