diff --git a/UnitTests/HttpInterface/api-collection-spec.rb b/UnitTests/HttpInterface/api-collection-mmfiles-spec.rb
similarity index 100%
rename from UnitTests/HttpInterface/api-collection-spec.rb
rename to UnitTests/HttpInterface/api-collection-mmfiles-spec.rb
diff --git a/UnitTests/HttpInterface/api-collection-rocksdb-spec.rb b/UnitTests/HttpInterface/api-collection-rocksdb-spec.rb
new file mode 100644
index 0000000000..6a433df9ec
--- /dev/null
+++ b/UnitTests/HttpInterface/api-collection-rocksdb-spec.rb
@@ -0,0 +1,937 @@
+# coding: utf-8
+
+require 'rspec'
+require 'arangodb.rb'
+
+describe ArangoDB do
+  api = "/_api/collection"
+  prefix = "api-collection"
+
+  context "dealing with collections:" do
+
+################################################################################
+## reading all collections
+################################################################################
+
+    context "all collections:" do
+      before do
+        for cn in ["units", "employees", "locations" ] do
+          ArangoDB.drop_collection(cn)
+          @cid = ArangoDB.create_collection(cn)
+        end
+      end
+
+      after do
+        for cn in ["units", "employees", "locations" ] do
+          ArangoDB.drop_collection(cn)
+        end
+      end
+
+      it "returns all collections" do
+        cmd = api
+        doc = ArangoDB.log_get("#{prefix}-all-collections", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+
+        collections = doc.parsed_response["result"];
+
+        total = 0
+        realCollections = [ ]
+        collections.each { |collection|
+          if [ "units", "employees", "locations" ].include? collection["name"]
+            realCollections.push(collection)
+          end
+          total = total + 1
+        }
+
+        realCollections.length.should eq(3)
+        total.should be > 3
+      end
+
+      it "returns all collections, exclude system collections" do
+        cmd = api + '/?excludeSystem=true'
+        doc = ArangoDB.log_get("#{prefix}-all-collections-nosystem", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        
+        collections = doc.parsed_response["result"]
+        realCollections = [ ]
+
+        total = 0
+        collections.each { |collection|
+          if [ "units", "employees", "locations" ].include? collection["name"]
+            realCollections.push(collection)
+          end
+          total = total + 1
+        }
+
+        realCollections.length.should eq(3)
+        total.should >= 3
+      end
+
+    end
+
+################################################################################
+## error handling
+################################################################################
+
+    context "error handling:" do
+      it "returns an error if collection identifier is unknown" do
+        cmd = api + "/123456"
+        doc = ArangoDB.log_get("#{prefix}-bad-identifier", cmd)
+
+        doc.code.should eq(404)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['errorNum'].should eq(1203)
+        doc.parsed_response['code'].should eq(404)
+      end
+
+      it "creating a collection without name" do
+        cmd = api
+        doc = ArangoDB.log_post("#{prefix}-create-missing-name", cmd)
+
+        doc.code.should eq(400)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(400)
+        doc.parsed_response['errorNum'].should eq(1208)
+      end
+
+      it "creating a collection with an illegal name" do
+        cmd = api
+        body = "{ \"name\" : \"1\" }"
+        doc = ArangoDB.log_post("#{prefix}-create-illegal-name", cmd, :body => body)
+
+        doc.code.should eq(400)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(400)
+        doc.parsed_response['errorNum'].should eq(1208)
+      end
+
+      it "creating a collection with a duplicate name" do
+        cn = "UnitTestsCollectionBasics"
+        cid = ArangoDB.create_collection(cn)
+
+        cmd = api
+        body = "{ \"name\" : \"#{cn}\" }"
+              doc = ArangoDB.log_post("#{prefix}-create-illegal-name", cmd, :body => body)
+
+        doc.code.should eq(409)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(409)
+        doc.parsed_response['errorNum'].should eq(1207)
+      end
+
+      it "creating a collection with an illegal body" do
+        cmd = api
+        body = "{ name : world }"
+              doc = ArangoDB.log_post("#{prefix}-create-illegal-body", cmd, :body => body)
+
+        doc.code.should eq(400)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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 in JSON at position 2")
+      end
+
+      it "creating a collection with a null body" do
+        cmd = api
+        body = "null"
+              doc = ArangoDB.log_post("#{prefix}-create-null-body", cmd, :body => body)
+
+        doc.code.should eq(400)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(400)
+        doc.parsed_response['errorNum'].should eq(1208)
+      end
+    end
+
+################################################################################
+## reading a collection
+################################################################################
+
+    context "reading:" do
+      before do
+        @cn = "UnitTestsCollectionBasics"
+        ArangoDB.drop_collection(@cn)
+        @cid = ArangoDB.create_collection(@cn)
+      end
+
+      after do
+        ArangoDB.drop_collection(@cn)
+      end
+
+      # get
+      it "finds the collection by identifier" do
+        cmd = api + "/" + String(@cid)
+        doc = ArangoDB.log_get("#{prefix}-get-collection-identifier", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+
+        cmd2 = api + "/" + @cn + "/unload"
+        doc = ArangoDB.put(cmd2)
+
+        doc = ArangoDB.log_get("#{prefix}-get-collection-identifier", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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].should include(doc.parsed_response['status'])
+      end
+
+      # get
+      it "finds the collection by name" do
+        cmd = api + "/" + @cn
+        doc = ArangoDB.log_get("#{prefix}-get-collection-name", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+
+        cmd2 = api + "/" + @cn + "/unload"
+        doc = ArangoDB.put(cmd2)
+
+        doc = ArangoDB.log_get("#{prefix}-get-collection-name", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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].should include(doc.parsed_response['status'])
+      end
+
+      # get count
+      it "checks the size of a collection" do
+        cmd = api + "/" + @cn + "/count"
+        doc = ArangoDB.log_get("#{prefix}-get-collection-count", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+      end
+
+      # get count
+      it "checks the properties of a collection" do
+        cmd = api + "/" + @cn + "/properties"
+        doc = ArangoDB.log_get("#{prefix}-get-collection-properties", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        doc.parsed_response['isSystem'].should eq(false)
+      end
+      
+      describe "figures", :timecritical => true do
+        # get figures
+        it "extracting the figures for a collection" do
+          # flush wal
+          ArangoDB.put("/_admin/wal/flush?waitForSync=true&waitForCollector=true", { })
+          sleep 3
+
+          cmd = api + "/" + @cn + "/figures"
+          doc = ArangoDB.log_get("#{prefix}-get-collection-figures", cmd)
+
+          doc.code.should eq(200)
+          doc.headers['content-type'].should eq("application/json; charset=utf-8")
+          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.parsed_response['count'].should eq(0)
+          doc.parsed_response['figures']['dead']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['dead']['count'].should eq(0)
+          doc.parsed_response['figures']['alive']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['alive']['count'].should eq(0)
+          doc.parsed_response['figures']['datafiles']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['datafiles']['fileSize'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['datafiles']['count'].should eq(0)
+          doc.parsed_response['figures']['journals']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['journals']['fileSize'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['journals']['count'].should eq(0)
+          doc.parsed_response['figures']['compactors']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['compactors']['fileSize'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['compactors']['count'].should eq(0)
+          doc.parsed_response['journalSize'].should be_kind_of(Integer)
+                
+          # create a few documents, this should increase counts
+          (0...10).each{|i|
+            body = "{ \"test\" : " + i.to_s + " }"
+            doc = ArangoDB.log_post("#{prefix}-get-collection-figures", "/_api/document/?collection=" + @cn, :body => body)
+          }
+
+          # flush wal
+          ArangoDB.put("/_admin/wal/flush?waitForSync=true&waitForCollector=true", { })
+          sleep 6
+          
+          doc = ArangoDB.log_get("#{prefix}-get-collection-figures", cmd)
+          doc.code.should eq(200)
+          doc.headers['content-type'].should eq("application/json; charset=utf-8")
+          doc.parsed_response['error'].should eq(false)
+          doc.parsed_response['code'].should eq(200)
+          doc.parsed_response['count'].should be_kind_of(Integer)
+          doc.parsed_response['count'].should eq(10)
+          doc.parsed_response['figures']['dead']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['dead']['count'].should eq(0)
+          doc.parsed_response['figures']['alive']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['alive']['count'].should eq(10)
+          doc.parsed_response['figures']['datafiles']['count'].should eq(0)
+          doc.parsed_response['figures']['journals']['count'].should eq(1)
+
+          # create a few different documents, this should increase counts
+          (0...10).each{|i|
+            body = "{ \"test" + i.to_s + "\" : 1 }"
+            doc = ArangoDB.log_post("#{prefix}-get-collection-figures", "/_api/document/?collection=" + @cn, :body => body)
+          }
+          
+          # flush wal
+          ArangoDB.put("/_admin/wal/flush?waitForSync=true&waitForCollector=true", { })
+          sleep 6
+          
+          doc = ArangoDB.log_get("#{prefix}-get-collection-figures", cmd)
+          doc.code.should eq(200)
+          doc.headers['content-type'].should eq("application/json; charset=utf-8")
+          doc.parsed_response['error'].should eq(false)
+          doc.parsed_response['code'].should eq(200)
+          doc.parsed_response['count'].should be_kind_of(Integer)
+          doc.parsed_response['count'].should eq(20)
+          doc.parsed_response['figures']['dead']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['dead']['count'].should eq(0)
+          doc.parsed_response['figures']['alive']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['alive']['count'].should eq(20)
+          doc.parsed_response['figures']['datafiles']['count'].should eq(0)
+          doc.parsed_response['figures']['journals']['count'].should eq(1)
+          
+          # delete a few documents, this should change counts
+          body = "{ \"collection\" : \"" + @cn + "\", \"example\": { \"test\" : 5 } }"
+          doc = ArangoDB.log_put("#{prefix}-get-collection-figures", "/_api/simple/remove-by-example", :body => body)
+          body = "{ \"collection\" : \"" + @cn + "\", \"example\": { \"test3\" : 1 } }"
+          doc = ArangoDB.log_put("#{prefix}-get-collection-figures", "/_api/simple/remove-by-example", :body => body)
+          
+          # flush wal
+          ArangoDB.put("/_admin/wal/flush?waitForSync=true&waitForCollector=true", { })
+          sleep 3
+          
+          doc = ArangoDB.log_get("#{prefix}-get-collection-figures", cmd)
+          doc.code.should eq(200)
+          doc.headers['content-type'].should eq("application/json; charset=utf-8")
+          doc.parsed_response['error'].should eq(false)
+          doc.parsed_response['code'].should eq(200)
+          doc.parsed_response['count'].should be_kind_of(Integer)
+          doc.parsed_response['count'].should eq(18)
+          doc.parsed_response['figures']['dead']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['dead']['count'].should eq(2)
+          doc.parsed_response['figures']['alive']['count'].should be_kind_of(Integer)
+          doc.parsed_response['figures']['alive']['count'].should eq(18)
+          doc.parsed_response['figures']['datafiles']['count'].should eq(0)
+          doc.parsed_response['figures']['journals']['count'].should eq(1)
+        end
+      end
+      
+      # get revision id
+      it "extracting the revision id of a collection" do
+        cmd = api + "/" + @cn + "/revision"
+        doc = ArangoDB.log_get("#{prefix}-get-collection-revision", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        r1 = doc.parsed_response['revision']
+        r1.should be_kind_of(String)
+        r1.should_not eq("");
+
+        # create a new document
+        body = "{ \"test\" : 1 }"
+        doc = ArangoDB.log_post("#{prefix}-get-collection-revision", "/_api/document/?collection=" + @cn, :body => body)
+        
+        # fetch revision again
+        doc = ArangoDB.log_get("#{prefix}-get-collection-revision", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['revision'].should be_kind_of(String)
+
+        r2 = doc.parsed_response['revision']
+        r2.should_not eq("");
+        r2.should_not eq(r1);
+        
+        # create another document
+        doc = ArangoDB.log_post("#{prefix}-get-collection-revision", "/_api/document/?collection=" + @cn, :body => body)
+        
+        # fetch revision again
+        doc = ArangoDB.log_get("#{prefix}-get-collection-revision", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['revision'].should be_kind_of(String)
+
+        r3 = doc.parsed_response['revision']
+        r3.should_not eq("");
+        r3.should_not eq(r1);
+        r3.should_not eq(r2);
+
+        # truncate
+        doc = ArangoDB.log_put("#{prefix}-get-collection-revision", "/_api/collection/#{@cn}/truncate", :body => "")
+        
+        # fetch revision again
+        doc = ArangoDB.log_get("#{prefix}-get-collection-revision", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['revision'].should be_kind_of(String)
+
+        r4 = doc.parsed_response['revision']
+        r4.should_not eq("");
+        r4.should_not eq(r1);
+        r4.should_not eq(r2);
+        r4.should_not eq(r3);
+      end
+    end
+
+################################################################################
+## deleting of collection
+################################################################################
+
+    context "deleting:" do
+      before do
+        @cn = "UnitTestsCollectionBasics"
+      end
+
+      it "delete an existing collection by identifier" do
+        cid = ArangoDB.create_collection(@cn)
+        cmd = api + "/" + @cn
+        doc = ArangoDB.log_delete("#{prefix}-delete-collection-identifier", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['id'].should eq(cid)
+
+        cmd = api + "/" + @cn
+        doc = ArangoDB.get(cmd)
+
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(404)
+      end
+
+      it "delete an existing collection by name" do
+        cid = ArangoDB.create_collection(@cn)
+        cmd = api + "/" + @cn
+        doc = ArangoDB.log_delete("#{prefix}-delete-collection-name", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['id'].should eq(cid)
+
+        cmd = api + "/" + @cn
+        doc = ArangoDB.get(cmd)
+
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(404)
+      end
+    end
+
+################################################################################
+## creating a collection
+################################################################################
+
+    context "creating:" do
+      before do
+        @cn = "UnitTestsCollectionBasics"
+      end
+
+      it "create a collection" do
+        cmd = api
+        body = "{ \"name\" : \"#{@cn}\" }"
+        doc = ArangoDB.log_post("#{prefix}-create-collection", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['id'].should be_kind_of(String) 
+        doc.parsed_response['name'].should eq(@cn)
+        doc.parsed_response['waitForSync'].should eq(false)
+
+        cmd = api + "/" + @cn + "/figures"
+        doc = ArangoDB.get(cmd)
+
+        doc.parsed_response['waitForSync'].should eq(false)
+
+        ArangoDB.drop_collection(@cn)
+      end
+
+      it "create a collection, sync" do
+        cmd = api
+        body = "{ \"name\" : \"#{@cn}\", \"waitForSync\" : true }"
+        doc = ArangoDB.log_post("#{prefix}-create-collection-sync", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['id'].should be_kind_of(String)
+        doc.parsed_response['name'].should eq(@cn)
+        doc.parsed_response['waitForSync'].should eq(true)
+
+        cmd = api + "/" + @cn + "/figures"
+        doc = ArangoDB.get(cmd)
+
+        doc.parsed_response['waitForSync'].should eq(true)
+
+        ArangoDB.drop_collection(@cn)
+      end
+      
+      it "create a collection, volatile" do
+        cmd = api
+        body = "{ \"name\" : \"#{@cn}\", \"isVolatile\" : true }"
+        doc = ArangoDB.log_post("#{prefix}-create-collection-volatile", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['id'].should be_kind_of(String)
+        doc.parsed_response['name'].should eq(@cn)
+        doc.parsed_response['waitForSync'].should eq(false)
+        doc.parsed_response['isVolatile'].should eq(true)
+        doc.parsed_response['isSystem'].should eq(false)
+
+        cmd = api + "/" + @cn + "/figures"
+        doc = ArangoDB.get(cmd)
+
+        doc.parsed_response['waitForSync'].should eq(false)
+
+        ArangoDB.drop_collection(@cn)
+      end
+            
+      it "create a collection, invalid name" do
+        cmd = api
+        body = "{ \"name\" : \"_invalid\" }"
+        doc = ArangoDB.log_post("#{prefix}-create-collection-invalid", cmd, :body => body)
+
+        doc.code.should eq(400)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(400)
+      end
+      
+      it "create a collection, already existing" do
+        ArangoDB.drop_collection(@cn)
+        cmd = api
+        body = "{ \"name\" : \"#{@cn}\" }"
+        doc = ArangoDB.log_post("#{prefix}-create-collection-existing", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+              
+        body = "{ \"name\" : \"#{@cn}\" }"
+        doc = ArangoDB.log_post("#{prefix}-create-collection-existing", cmd, :body => body)
+
+        doc.code.should eq(409)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(true)
+        doc.parsed_response['code'].should eq(409)
+  
+        ArangoDB.drop_collection(@cn)
+      end
+    end
+
+################################################################################
+## load a collection
+################################################################################
+
+    context "loading:" do
+      before do
+        @cn = "UnitTestsCollectionBasics"
+      end
+
+      it "load a collection by identifier" do
+        ArangoDB.drop_collection(@cn)
+        cid = ArangoDB.create_collection(@cn)
+
+        cmd = api + "/" + @cn + "/load"
+        doc = ArangoDB.log_put("#{prefix}-identifier-load", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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.parsed_response['count'].should eq(0)
+
+        ArangoDB.drop_collection(@cn)
+      end
+
+      it "load a collection by name" do
+        ArangoDB.drop_collection(@cn)
+        cid = ArangoDB.create_collection(@cn)
+
+        cmd = api + "/" + @cn + "/load"
+        doc = ArangoDB.log_put("#{prefix}-name-load", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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.parsed_response['count'].should eq(0)
+
+        ArangoDB.drop_collection(@cn)
+      end
+
+      it "load a collection by name with explicit count" do
+        ArangoDB.drop_collection(@cn)
+        cid = ArangoDB.create_collection(@cn)
+
+        cmd = "/_api/document?collection=#{@cn}"
+        body = "{ \"Hallo\" : \"World\" }"
+
+        for i in ( 1 .. 10 )
+          doc = ArangoDB.post(cmd, :body => body)
+        end
+
+        cmd = api + "/" + @cn + "/load"
+        body = "{ \"count\" : true }"
+        doc = ArangoDB.log_put("#{prefix}-name-load", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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.parsed_response['count'].should eq(10)
+
+        ArangoDB.drop_collection(@cn)
+      end
+
+      it "load a collection by name without count" do
+        ArangoDB.drop_collection(@cn)
+        cid = ArangoDB.create_collection(@cn)
+        
+        cmd = "/_api/document?collection=#{@cn}"
+        body = "{ \"Hallo\" : \"World\" }"
+        doc = ArangoDB.post(cmd, :body => body)
+
+        cmd = api + "/" + @cn + "/load"
+        body = "{ \"count\" : false }"
+        doc = ArangoDB.log_put("#{prefix}-name-load", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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_nil
+
+        ArangoDB.drop_collection(@cn)
+      end
+    end
+
+################################################################################
+## unloading a collection
+################################################################################
+
+    context "unloading:" do
+      before do
+        @cn = "UnitTestsCollectionBasics"
+      end
+
+      it "unload a collection by identifier" do
+        ArangoDB.drop_collection(@cn)
+        cid = ArangoDB.create_collection(@cn)
+
+        cmd = api + "/" + @cn + "/unload"
+        doc = ArangoDB.log_put("#{prefix}-identifier-unload", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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].should include(doc.parsed_response['status'])
+
+        ArangoDB.drop_collection(@cn)
+      end
+
+      it "unload a collection by name" do
+        ArangoDB.drop_collection(@cn)
+        cid = ArangoDB.create_collection(@cn)
+
+        cmd = api + "/" + @cn + "/unload"
+        doc = ArangoDB.log_put("#{prefix}-name-unload", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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].should include(doc.parsed_response['status'])
+
+        ArangoDB.drop_collection(@cn)
+      end
+    end
+
+################################################################################
+## truncate a collection
+################################################################################
+
+    context "truncating:" do
+      before do
+        @cn = "UnitTestsCollectionBasics"
+        @cid = ArangoDB.create_collection(@cn)
+      end
+
+      after do
+        ArangoDB.drop_collection(@cn)
+      end
+
+      it "truncate a collection by identifier" do
+        cmd = "/_api/document?collection=#{@cid}"
+        body = "{ \"Hallo\" : \"World\" }"
+
+        for i in ( 1 .. 10 )
+          doc = ArangoDB.post(cmd, :body => body)
+        end
+
+        ArangoDB.size_collection(@cid).to_i.should eq(10)
+
+        cmd = api + "/" + @cn + "/truncate"
+        doc = ArangoDB.log_put("#{prefix}-identifier-truncate", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+
+        ArangoDB.size_collection(@cid).should eq(0)
+
+        ArangoDB.drop_collection(@cn)
+      end
+    end
+
+################################################################################
+## properties of a collection
+################################################################################
+
+    context "properties:" do
+      it "changing the properties of a collection by identifier" do
+        cn = "UnitTestsCollectionBasics"
+        ArangoDB.drop_collection(cn)
+        cid = ArangoDB.create_collection(cn)
+
+        cmd = "/_api/document?collection=#{cid}"
+        body = "{ \"Hallo\" : \"World\" }"
+
+        for i in ( 1 .. 10 )
+          doc = ArangoDB.post(cmd, :body => body)
+        end
+
+        ArangoDB.size_collection(cid).should eq(10)
+        ArangoDB.size_collection(cn).should eq(10)
+
+        cmd = api + "/" + cn + "/properties"
+        body = "{ \"waitForSync\" : true }"
+        doc = ArangoDB.log_put("#{prefix}-identifier-properties-sync", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        doc.parsed_response['isSystem'].should eq(false)
+        doc.parsed_response['keyOptions']['type'].should eq("traditional")
+        doc.parsed_response['keyOptions']['allowUserKeys'].should eq(true)
+
+        cmd = api + "/" + cn + "/properties"
+        body = "{ \"waitForSync\" : false }"
+        doc = ArangoDB.log_put("#{prefix}-identifier-properties-no-sync", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        doc.parsed_response['isSystem'].should eq(false)
+        doc.parsed_response['keyOptions']['type'].should eq("traditional")
+        doc.parsed_response['keyOptions']['allowUserKeys'].should eq(true)
+        
+        body = "{ \"doCompact\" : false }"
+        doc = ArangoDB.log_put("#{prefix}-identifier-properties-no-compact", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        doc.parsed_response['isSystem'].should eq(false)
+        doc.parsed_response['keyOptions']['type'].should eq("traditional")
+        doc.parsed_response['keyOptions']['allowUserKeys'].should eq(true)
+
+        ArangoDB.drop_collection(cn)
+      end
+
+      it "create collection with explicit keyOptions property, traditional keygen" do
+        cn = "UnitTestsCollectionBasics"
+
+        cmd = "/_api/collection"
+        body = "{ \"name\" : \"#{cn}\", \"waitForSync\" : false, \"type\" : 2, \"keyOptions\" : {\"type\": \"traditional\", \"allowUserKeys\": true } }"
+        doc = ArangoDB.log_post("#{prefix}-with-create-options", cmd, :body => body)
+
+        doc.code.should eq(200)
+        cid = doc.parsed_response['id']
+
+        cmd = api + "/" + cn + "/properties"
+        body = "{ \"waitForSync\" : true }"
+        doc = ArangoDB.log_put("#{prefix}-with-create-options", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        doc.parsed_response['isVolatile'].should eq(false)
+        doc.parsed_response['keyOptions']['type'].should eq("traditional")
+        doc.parsed_response['keyOptions']['allowUserKeys'].should eq(true)
+
+        ArangoDB.drop_collection(cn)
+      end
+
+      it "create a collection with isVolatile property" do
+        cn = "UnitTestsCollectionBasics"
+        ArangoDB.drop_collection(cn)
+
+        cmd = "/_api/collection"
+        body = "{ \"name\" : \"#{cn}\", \"isVolatile\" : true }"
+        doc = ArangoDB.log_post("#{prefix}-with-volatile", cmd, :body => body)
+
+        doc.code.should eq(200)
+        cid = doc.parsed_response['id']
+
+        cmd = api + "/" + cn + "/properties"
+        doc = ArangoDB.log_get("#{prefix}-with-volatile", cmd)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        doc.parsed_response['error'].should eq(false)
+        doc.parsed_response['code'].should eq(200)
+        doc.parsed_response['waitForSync'].should eq(false)
+        doc.parsed_response['keyOptions']['type'].should eq("traditional")
+        doc.parsed_response['keyOptions']['allowUserKeys'].should eq(true)
+
+        ArangoDB.drop_collection(cn)
+      end
+      
+      it "create collection with empty keyOptions property" do
+        cn = "UnitTestsCollectionBasics"
+        ArangoDB.drop_collection(cn)
+
+        cmd = "/_api/collection"
+        body = "{ \"name\" : \"#{cn}\", \"waitForSync\" : false, \"type\" : 2 }"
+        doc = ArangoDB.log_post("#{prefix}-with-empty-create-options", cmd, :body => body)
+
+        doc.code.should eq(200)
+        cid = doc.parsed_response['id']
+
+        cmd = api + "/" + cn + "/properties"
+        body = "{ \"waitForSync\" : true }"
+        doc = ArangoDB.log_put("#{prefix}-with-empty-create-options", cmd, :body => body)
+
+        doc.code.should eq(200)
+        doc.headers['content-type'].should eq("application/json; charset=utf-8")
+        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)
+        doc.parsed_response['keyOptions']['type'].should eq("traditional")
+        doc.parsed_response['keyOptions']['allowUserKeys'].should eq(true)
+
+        ArangoDB.drop_collection(cn)
+      end
+
+    end
+
+  end
+end
diff --git a/arangod/RocksDBEngine/RocksDBCollection.cpp b/arangod/RocksDBEngine/RocksDBCollection.cpp
index 1653f72efa..bce22e3049 100644
--- a/arangod/RocksDBEngine/RocksDBCollection.cpp
+++ b/arangod/RocksDBEngine/RocksDBCollection.cpp
@@ -553,8 +553,9 @@ int RocksDBCollection::update(arangodb::transaction::Methods* trx,
     return res;
   }
 
-  uint8_t const* vpack = previous.vpack();
-  VPackSlice oldDoc(vpack);
+  TRI_ASSERT(!previous.empty());
+
+  VPackSlice oldDoc(previous.vpack());
   TRI_voc_rid_t oldRevisionId =
       transaction::helpers::extractRevFromDocument(oldDoc);
   prevRev = oldRevisionId;
@@ -574,6 +575,8 @@ int RocksDBCollection::update(arangodb::transaction::Methods* trx,
   if (newSlice.length() <= 1) {
     // shortcut. no need to do anything
     previous.clone(mdr);
+  
+    TRI_ASSERT(!mdr.empty());
 
     if (_logicalCollection->waitForSync()) {
       trx->state()->waitForSync(true);
@@ -611,6 +614,8 @@ int RocksDBCollection::update(arangodb::transaction::Methods* trx,
     if (!result.ok()) {
       return result.errorNumber();
     }
+  
+    TRI_ASSERT(!mdr.empty());
     
     static_cast<RocksDBTransactionState*>(trx->state())->addOperation(_logicalCollection->cid(), TRI_VOC_DOCUMENT_OPERATION_UPDATE, newDoc.byteSize());
     guard.commit();
@@ -643,9 +648,10 @@ int RocksDBCollection::replace(
   if (res != TRI_ERROR_NO_ERROR) {
     return res;
   }
+    
+  TRI_ASSERT(!previous.empty());
 
-  uint8_t const* vpack = previous.vpack();
-  VPackSlice oldDoc(vpack);
+  VPackSlice oldDoc(previous.vpack());
   TRI_voc_rid_t oldRevisionId =
       transaction::helpers::extractRevFromDocument(oldDoc);
   prevRev = oldRevisionId;
@@ -689,6 +695,8 @@ int RocksDBCollection::replace(
     if (!result.ok()) {
       return result.errorNumber();
     }
+  
+    TRI_ASSERT(!mdr.empty());
 
     static_cast<RocksDBTransactionState*>(trx->state())->addOperation(_logicalCollection->cid(), TRI_VOC_DOCUMENT_OPERATION_REPLACE, VPackSlice(builder->slice()).byteSize());
     guard.commit();
@@ -726,9 +734,10 @@ int RocksDBCollection::remove(arangodb::transaction::Methods* trx,
   if (res != TRI_ERROR_NO_ERROR) {
     return res;
   }
+  
+  TRI_ASSERT(!previous.empty());
 
-  uint8_t const* vpack = previous.vpack();
-  VPackSlice oldDoc(vpack);
+  VPackSlice oldDoc(previous.vpack());
   TRI_voc_rid_t oldRevisionId =
       arangodb::transaction::helpers::extractRevFromDocument(oldDoc);
   prevRev = oldRevisionId;
@@ -1058,6 +1067,7 @@ arangodb::Result RocksDBCollection::lookupRevisionVPack(
         << "', OBJECTID: " << _objectId << ", REVISIONID: " << revisionId
         << " -> NOT FOUND";
     */
+    mdr.reset();
   }
   return result;
 }
diff --git a/arangod/RocksDBEngine/RocksDBEngine.cpp b/arangod/RocksDBEngine/RocksDBEngine.cpp
index f28d3722fa..dba335add8 100644
--- a/arangod/RocksDBEngine/RocksDBEngine.cpp
+++ b/arangod/RocksDBEngine/RocksDBEngine.cpp
@@ -92,7 +92,15 @@ void RocksDBEngine::validateOptions(std::shared_ptr<options::ProgramOptions>) {}
 
 // preparation phase for storage engine. can be used for internal setup.
 // the storage engine must not start any threads here or write any files
-void RocksDBEngine::prepare() {}
+void RocksDBEngine::prepare() {
+  // get base path from DatabaseServerFeature
+  auto databasePathFeature =
+      application_features::ApplicationServer::getFeature<DatabasePathFeature>(
+          "DatabasePath");
+  _basePath = databasePathFeature->directory();
+  
+  TRI_ASSERT(!_basePath.empty());
+}
 
 void RocksDBEngine::start() {
   // it is already decided that rocksdb is used
@@ -342,7 +350,7 @@ int RocksDBEngine::getViews(TRI_vocbase_t* vocbase,
 }
 
 std::string RocksDBEngine::databasePath(TRI_vocbase_t const* vocbase) const {
-  return std::string();  // no path to be returned here!
+  return _basePath;
 }
 
 std::string RocksDBEngine::collectionPath(TRI_vocbase_t const* vocbase,
@@ -733,9 +741,7 @@ Result RocksDBEngine::dropDatabase(TRI_voc_tick_t id) {
     // delete index documents
     uint64_t objectId =
         basics::VelocyPackHelper::stringUInt64(val.second.slice(), "objectId");
-    RocksDBKeyBounds bounds = RocksDBKeyBounds::IndexRange(
-        objectId, VPackSlice::minKeySlice(), VPackSlice::maxKeySlice()
-    );
+    RocksDBKeyBounds bounds = RocksDBKeyBounds::IndexEntries(objectId);
     res = rocksutils::removeLargeRange(_db, bounds);
     if(res.fail()){
       return res;
diff --git a/arangod/RocksDBEngine/RocksDBEngine.h b/arangod/RocksDBEngine/RocksDBEngine.h
index d03511cdb9..7beafe7e8c 100644
--- a/arangod/RocksDBEngine/RocksDBEngine.h
+++ b/arangod/RocksDBEngine/RocksDBEngine.h
@@ -260,6 +260,7 @@ class RocksDBEngine final : public StorageEngine {
   rocksdb::Options _options;
   std::unique_ptr<RocksDBComparator> _cmp;
   std::string _path;
+  std::string _basePath;
 
   std::unique_ptr<RocksDBCounterManager> _counterManager;
 };
diff --git a/arangod/RocksDBEngine/RocksDBKeyBounds.cpp b/arangod/RocksDBEngine/RocksDBKeyBounds.cpp
index a8b88b1a6a..474f7a1d98 100644
--- a/arangod/RocksDBEngine/RocksDBKeyBounds.cpp
+++ b/arangod/RocksDBEngine/RocksDBKeyBounds.cpp
@@ -70,7 +70,7 @@ RocksDBKeyBounds RocksDBKeyBounds::EdgeIndexVertex(
   return RocksDBKeyBounds(RocksDBEntryType::EdgeIndexValue, indexId, vertexId);
 }
 
-RocksDBKeyBounds RocksDBKeyBounds::Index(uint64_t indexId) {
+RocksDBKeyBounds RocksDBKeyBounds::IndexEntries(uint64_t indexId) {
   return RocksDBKeyBounds(RocksDBEntryType::IndexValue, indexId);
 }
 
diff --git a/arangod/RocksDBEngine/RocksDBKeyBounds.h b/arangod/RocksDBEngine/RocksDBKeyBounds.h
index 7c95c8129f..6bfb33b8ee 100644
--- a/arangod/RocksDBEngine/RocksDBKeyBounds.h
+++ b/arangod/RocksDBEngine/RocksDBKeyBounds.h
@@ -86,7 +86,7 @@ class RocksDBKeyBounds {
   //////////////////////////////////////////////////////////////////////////////
   /// @brief Bounds for all index-entries belonging to a specified non-unique index
   //////////////////////////////////////////////////////////////////////////////
-  static RocksDBKeyBounds Index(uint64_t indexId);
+  static RocksDBKeyBounds IndexEntries(uint64_t indexId);
 
   //////////////////////////////////////////////////////////////////////////////
   /// @brief Bounds for all entries belonging to a specified unique index
diff --git a/arangod/RocksDBEngine/RocksDBVPackIndex.cpp b/arangod/RocksDBEngine/RocksDBVPackIndex.cpp
index 1061497c26..c0a745d386 100644
--- a/arangod/RocksDBEngine/RocksDBVPackIndex.cpp
+++ b/arangod/RocksDBEngine/RocksDBVPackIndex.cpp
@@ -584,7 +584,7 @@ int RocksDBVPackIndex::drop() {
         rocksutils::globalRocksDB(), RocksDBKeyBounds::UniqueIndex(_objectId)).errorNumber();
   } else {
     return rocksutils::removeLargeRange(rocksutils::globalRocksDB(),
-                                        RocksDBKeyBounds::Index(_objectId)).errorNumber();
+                                        RocksDBKeyBounds::IndexEntries(_objectId)).errorNumber();
   }
 }
 
diff --git a/arangod/Transaction/Methods.cpp b/arangod/Transaction/Methods.cpp
index b451c2cf8a..e25d769ec4 100644
--- a/arangod/Transaction/Methods.cpp
+++ b/arangod/Transaction/Methods.cpp
@@ -826,15 +826,11 @@ OperationResult transaction::Methods::anyLocal(std::string const& collectionName
                 limit, 1000, false);
 
   LogicalCollection* collection = cursor->collection();
-  auto cb = [&] (DocumentIdentifierToken const& token) {
+  cursor->getAll([&] (DocumentIdentifierToken const& token) {
     if (collection->readDocument(this, token, mmdr)) {
-      uint8_t const* vpack = mmdr.vpack();
-      resultBuilder.add(VPackSlice(vpack));
+      mmdr.addToBuilder(resultBuilder, false);
     }
-  };
-
-  while (cursor->getMore(cb, 1000)) {
-  }
+  });
 
   resultBuilder.close();
 
@@ -1001,8 +997,6 @@ Result transaction::Methods::documentFastPath(std::string const& collectionName,
   
   TRI_ASSERT(isPinned(cid));
 
-  uint8_t const* vpack = mmdr->vpack();
-  TRI_ASSERT(vpack != nullptr);
   mmdr->addToBuilder(result, true);
   return TRI_ERROR_NO_ERROR;
 }
@@ -1214,10 +1208,8 @@ OperationResult transaction::Methods::documentLocal(std::string const& collectio
   
     TRI_ASSERT(isPinned(cid));
 
-    uint8_t const* vpack = result.vpack();
-  
     if (expectedRevision != 0) {
-      TRI_voc_rid_t foundRevision = transaction::helpers::extractRevFromDocument(VPackSlice(vpack));
+      TRI_voc_rid_t foundRevision = transaction::helpers::extractRevFromDocument(VPackSlice(result.vpack()));
       if (expectedRevision != foundRevision) {
         if (!isMultiple) {
           // still return
@@ -1359,6 +1351,8 @@ OperationResult transaction::Methods::insertLocal(std::string const& collectionN
       // in the single document case no body needs to be created at all.
       return res;
     }
+    
+    TRI_ASSERT(!result.empty());
 
     StringRef keyString(transaction::helpers::extractKeyFromDocument(VPackSlice(result.vpack())));
 
@@ -1650,6 +1644,9 @@ OperationResult transaction::Methods::modifyLocal(
           !isLocked(collection, AccessMode::Type::WRITE), actualRevision,
           previous);
     }
+    
+    TRI_ASSERT(!result.empty());
+    TRI_ASSERT(!previous.empty());
 
     if (resultMarkerTick > 0 && resultMarkerTick > maxTick) {
       maxTick = resultMarkerTick;
@@ -1907,6 +1904,8 @@ OperationResult transaction::Methods::removeLocal(std::string const& collectionN
     if (resultMarkerTick > 0 && resultMarkerTick > maxTick) {
       maxTick = resultMarkerTick;
     }
+
+    TRI_ASSERT(!previous.empty());
     
     if (res != TRI_ERROR_NO_ERROR) {
       if (res == TRI_ERROR_ARANGO_CONFLICT && 
diff --git a/arangod/VocBase/ManagedDocumentResult.h b/arangod/VocBase/ManagedDocumentResult.h
index a407f9c204..2954d5d3ce 100644
--- a/arangod/VocBase/ManagedDocumentResult.h
+++ b/arangod/VocBase/ManagedDocumentResult.h
@@ -71,6 +71,7 @@ class ManagedDocumentResult {
       cloned._useString = true;
       cloned._string = _string;
       cloned._lastRevisionId = _lastRevisionId;
+      cloned._vpack = reinterpret_cast<uint8_t*>(const_cast<char*>(cloned._string.data()));
     } else if (_managed) {
       cloned.setManaged(_vpack, _lastRevisionId);
     } else {
diff --git a/js/server/upgrade-database.js b/js/server/upgrade-database.js
index c16f142199..81311c8311 100644
--- a/js/server/upgrade-database.js
+++ b/js/server/upgrade-database.js
@@ -94,10 +94,7 @@
     constant2name[DATABASE_EXISTING] = 'existing';
 
     // path to version file
-    let versionFile;
-    if (internal.db._path()) {
-      versionFile = internal.db._path() + '/VERSION';
-    }
+    let versionFile = internal.db._path() + '/VERSION';
 
     // all defined tasks
     const allTasks = [];
@@ -287,7 +284,7 @@
           lastTasks[task.name] = true;
 
           // save/update version info
-          if (isLocal && versionFile) {
+          if (isLocal) {
             fs.write(
               versionFile,
               JSON.stringify({
@@ -303,7 +300,7 @@
       }
 
       // save file so version gets saved even if there are no tasks
-      if (isLocal && versionFile) {
+      if (isLocal) {
         fs.write(
           versionFile,
           JSON.stringify({
@@ -350,7 +347,7 @@
       }
 
       // VERSION file exists, read its contents
-      if (versionFile && fs.exists(versionFile)) {
+      if (fs.exists(versionFile)) {
         var versionInfo = fs.read(versionFile);
 
         if (versionInfo === '') {
@@ -490,7 +487,7 @@
           return false;
         }
 
-        if (db._engine().name != "rocksdb") {
+        if (db._engine().name !== "rocksdb") {
           users.ensureIndex({
             type: 'hash',
             fields: ['user'],
diff --git a/tests/Basics/RocksDBKeyTest.cpp b/tests/Basics/RocksDBKeyTest.cpp
index 2c9fe61a3c..db19f23fde 100644
--- a/tests/Basics/RocksDBKeyTest.cpp
+++ b/tests/Basics/RocksDBKeyTest.cpp
@@ -79,6 +79,57 @@ SECTION("test_database") {
   
   CHECK(s6.size() == sizeof(char) + sizeof(uint64_t));
   CHECK(s6 == std::string("0\x35\x1c\xdc\xdf\x02\0\0\0", 9));
+  
+  RocksDBKey key7 = RocksDBKey::Database(0xf0f1f2f3f4f5f6f7ULL); 
+  auto const& s7 = key7.string();
+  
+  CHECK(s7.size() == sizeof(char) + sizeof(uint64_t));
+  CHECK(s7 == std::string("0\xf7\xf6\xf5\xf4\xf3\xf2\xf1\xf0", 9));
+}
+
+/// @brief test collection
+SECTION("test_collection") {
+  RocksDBKey key1 = RocksDBKey::Collection(0, 0); 
+  auto const& s1 = key1.string();
+  
+  CHECK(s1.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t));
+  CHECK(s1 == std::string("1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 17));
+  
+  RocksDBKey key2 = RocksDBKey::Collection(23, 42); 
+  auto const& s2 = key2.string();
+  
+  CHECK(s2.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t));
+  CHECK(s2 == std::string("1\x17\0\0\0\0\0\0\0\x2a\0\0\0\0\0\0\0", 17));
+  
+  RocksDBKey key3 = RocksDBKey::Collection(255, 255); 
+  auto const& s3 = key3.string();
+  
+  CHECK(s3.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t));
+  CHECK(s3 == std::string("1\xff\0\0\0\0\0\0\0\xff\0\0\0\0\0\0\0", 17));
+  
+  RocksDBKey key4 = RocksDBKey::Collection(256, 257); 
+  auto const& s4 = key4.string();
+  
+  CHECK(s4.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t));
+  CHECK(s4 == std::string("1\0\x01\0\0\0\0\0\0\x01\x01\0\0\0\0\0\0", 17));
+  
+  RocksDBKey key5 = RocksDBKey::Collection(49152, 16384); 
+  auto const& s5 = key5.string();
+  
+  CHECK(s5.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t));
+  CHECK(s5 == std::string("1\0\xc0\0\0\0\0\0\0\0\x40\0\0\0\0\0\0", 17));
+  
+  RocksDBKey key6 = RocksDBKey::Collection(12345678901, 987654321); 
+  auto const& s6 = key6.string();
+  
+  CHECK(s6.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t)) ;
+  CHECK(s6 == std::string("1\x35\x1c\xdc\xdf\x02\0\0\0\xb1\x68\xde\x3a\0\0\0\0", 17));
+  
+  RocksDBKey key7 = RocksDBKey::Collection(0xf0f1f2f3f4f5f6f7ULL, 0xf0f1f2f3f4f5f6f7ULL); 
+  auto const& s7 = key7.string();
+  
+  CHECK(s7.size() == sizeof(char) + sizeof(uint64_t) + sizeof(uint64_t));
+  CHECK(s7 == std::string("1\xf7\xf6\xf5\xf4\xf3\xf2\xf1\xf0\xf7\xf6\xf5\xf4\xf3\xf2\xf1\xf0", 17));
 }
 
 }