diff --git a/.travis.yml b/.travis.yml
index f3cf06e..7b188f5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,4 +6,3 @@ before_script:
 env:
   - ORIENTDB_VERSION=1.7.10
   - ORIENTDB_VERSION=2.0.2
-  - ORIENTDB_VERSION=2.1-SNAPSHOT
diff --git a/lib/db/class/index.js b/lib/db/class/index.js
index e42d89d..25d86db 100644
--- a/lib/db/class/index.js
+++ b/lib/db/class/index.js
@@ -204,9 +204,10 @@ exports.list = function (refresh) {
  * @param  {String} name            The name of the class to create.
  * @param  {String} parentName      The name of the parent to extend, if any.
  * @param  {String|Integer} cluster The cluster name or id.
+ * @param  {Boolean} isAbstract     The flag for the abstract class
  * @promise {Object}                The created class object
  */
-exports.create = function (name, parentName, cluster) {
+exports.create = function (name, parentName, cluster, isAbstract) {
   var query = 'CREATE CLASS ' + name;
 
   if (parentName) {
@@ -216,6 +217,10 @@ exports.create = function (name, parentName, cluster) {
   if (cluster) {
     query += ' CLUSTER ' + cluster;
   }
+  
+  if(isAbstract) {
+    query += ' ABSTRACT';
+  }
 
   return this.query(query)
   .bind(this)
@@ -296,4 +301,4 @@ exports.cacheData = function (classes) {
   }
 
   return this;
-};
\ No newline at end of file
+};
diff --git a/lib/db/class/property.js b/lib/db/class/property.js
index 9db2bcf..b512d56 100644
--- a/lib/db/class/property.js
+++ b/lib/db/class/property.js
@@ -35,8 +35,8 @@ Property.prototype.configure = function (config) {
   this.readonly = config.readonly || false;
   this.notNull = config.notNull || false;
   this.collate = config.collate || 'default';
-  this.min = config.min || null;
-  this.max = config.max || null;
+  this.min = typeof config.min !== 'undefined' ? config.min : null;
+  this.max = typeof config.max !== 'undefined' ? config.max : null;
   this.regexp = config.regexp || null;
   this.linkedClass = config.linkedClass || null;
   if (config.custom && config.custom.fields) {
diff --git a/lib/db/statement.js b/lib/db/statement.js
index 1e53a53..a76697e 100644
--- a/lib/db/statement.js
+++ b/lib/db/statement.js
@@ -31,6 +31,18 @@ Statement.prototype.select = clause('select', '*');
  */
 Statement.prototype.traverse = clause('traverse', '*');
 
+/**
+ * A 'strategy' clause for traverse query
+ * @param {String} args The strategy how traverse should go in deep,
+ *                      either 'DEPTH_FIRST'|'BREADTH_FIRST', the first one is default
+ * @return {Statement}  The statement object
+ */
+Statement.prototype.strategy = function (s) {
+  if (typeof s === 'string' && s.toUpperCase() === 'DEPTH_FIRST' || s.toUpperCase() === 'BREADTH_FIRST') {
+    this._state.strategy = s.toUpperCase();
+  }
+  return this;
+};
 
 /**
  * Insert expression.
@@ -813,6 +825,11 @@ Statement.prototype.buildStatement = function () {
   if (state.limit) {
     statement.push('LIMIT ' + (+state.limit));
   }
+
+  if (state.strategy && state.traverse) {
+    statement.push('STRATEGY ' + state.strategy);
+  }
+
   if (state.skip) {
     statement.push('SKIP ' + (+state.skip));
   }
@@ -1015,4 +1032,4 @@ function encodeReturnObject (obj) {
     parts[i] = utils.encode(key) + ":" + obj[key];
   }
   return '{'+parts.join(',')+'}';
-}
\ No newline at end of file
+}
diff --git a/test/db/statement-test.js b/test/db/statement-test.js
index 3b4e09e..9c20088 100644
--- a/test/db/statement-test.js
+++ b/test/db/statement-test.js
@@ -178,6 +178,26 @@ COMMIT \n\
       this.statement.traverse('in("Thing")', 'out("Thing")');
       this.statement.buildStatement().should.equal('TRAVERSE in("Thing"), out("Thing")');
     });
+
+    it('should traverse in depth first', function () {
+      this.statement.traverse().strategy('DEPTH_FIRST').from('Abc');
+      this.statement.buildStatement().should.equal('TRAVERSE * FROM Abc STRATEGY DEPTH_FIRST');
+    });
+
+    it('should traverse in breadth first', function () {
+      this.statement.traverse().strategy('BREADTH_FIRST').from('#23:4');
+      this.statement.buildStatement().should.equal('TRAVERSE * FROM #23:4 STRATEGY BREADTH_FIRST');
+    });
+
+    it('should traverse with no strategy spec', function () {
+      this.statement.traverse().strategy('XYZ');
+      this.statement.buildStatement().should.equal('TRAVERSE *');
+    });
+
+    it('should traverse in breadth first and with limit', function () {
+      this.statement.traverse().strategy('BREADTH_FIRST').limit(2).from('Xyz');
+      this.statement.buildStatement().should.equal('TRAVERSE * FROM Xyz LIMIT 2 STRATEGY BREADTH_FIRST');
+    });
   });
 
   describe('Statement::while()', function () {