diff --git a/ajax/documentController.php b/ajax/documentController.php
index e5622e03..733924b8 100644
--- a/ajax/documentController.php
+++ b/ajax/documentController.php
@@ -30,20 +30,21 @@ class DocumentController extends Controller{
 
 /**
 	 * Process partial/complete file download
-	 * @param array $args - array containing session id as anelement with a key es_id 
+	 * @param array $args - array containing session id as an element with a key es_id 
 	 */
 	public static function serve($args){
-		$session = Session::getSession(@$args['es_id']);
-		
-		$file = new File(@$session['file_id']);
+		$session = new Db_Session();
+		$sessionData = $session->load(@$args['es_id'])->getData();
+			
+		$file = new File(@$sessionData['file_id']);
 		if (!$file->isPublicShare()){
 			self::preDispatch(false);
 		} else {
 			self::preDispatchGuest(false);
 		}
 		
-		$filename = isset($session['genesis_url']) ? $session['genesis_url'] : '';
-		$documentsView = new View('/' . $session['owner']);
+		$filename = isset($sessionData['genesis_url']) ? $sessionData['genesis_url'] : '';
+		$documentsView = new View('/' . $sessionData['owner']);
 		$download = new Download($documentsView->initDocumentsView(), $filename);
 		$download->sendResponse();
 	}
@@ -66,11 +67,13 @@ class DocumentController extends Controller{
 			$fileIds[] = $document['fileid'];
 		}
 
-		$sessions = Session::getSessionsByFileIds($fileIds);
+		$session = new Db_Session();
+		$sessions = $session->getCollectionBy('file_id', $fileIds);
 
 		$members = array();
+		$member = new Db_Member();
 		foreach ($sessions as $session) {
-			$members[$session['es_id']] = Member::getMembersByEsId($session['es_id']);
+			$members[$session['es_id']] = $member->getCollectionBy('es_id', $session['es_id']);
 		}
 
 		\OCP\JSON::success(array('documents' => $documents,'sessions' => $sessions,'members' => $members));
diff --git a/ajax/otpoll.php b/ajax/otpoll.php
index ff6d6215..daf42544 100644
--- a/ajax/otpoll.php
+++ b/ajax/otpoll.php
@@ -43,8 +43,9 @@ try{
 	$request = new Request();
 	$esId = $request->getParam('args/es_id');
 	
-	$session = Session::getSession($esId);
-	$file = new File(@$session['file_id']);
+	$session = new Db_Session();
+	$sessionData = $session->load($esId)->getData();
+	$file = new File(@$sessionData['file_id']);
 	if (!$file->isPublicShare()){
 		Controller::preDispatch(false);
 	} else {
@@ -55,7 +56,10 @@ try{
 	switch ($command){
 		case 'query_memberdata_list':
 			$ids = $request->getParam('args/member_ids');
-			$members = Member::getMembersAsArray($ids);
+			
+			$member = new Db_Member();
+			$members = $member->getCollectionBy('member_id', $ids);
+			
 			$response["memberdata_list"] = array_map(
 					function($x){
 						$x['display_name'] = \OCP\User::getDisplayName($x['uid']);
@@ -91,11 +95,13 @@ try{
 				$ops = $request->getParam('args/client_ops');
 				$hasOps = is_array($ops) && count($ops)>0;
 
-				$currentHead = Op::getHeadSeq($esId);
+				$op = new Db_Op();
+				$currentHead = $op->getHeadSeq($esId);
+				
+				$member = new Db_Member();
 				try {
-					Member::updateMemberActivity($memberId);
+					$member->updateActivity($memberId);
 				} catch (\Exception $e){
-					
 				}
 
 				// TODO handle the case ($currentHead == "") && ($seqHead != "")
@@ -104,7 +110,7 @@ try{
 					if ($hasOps) {
 						// incoming ops without conflict
 						// Add incoming ops, respond with a new head
-						$newHead = Op::addOpsArray($esId, $memberId, $ops);
+						$newHead = Db_Op::addOpsArray($esId, $memberId, $ops);
 						$response["result"] = 'added';
 						$response["head_seq"] = $newHead ? $newHead : $currentHead;
 					} else {
@@ -114,18 +120,16 @@ try{
 						$response["head_seq"] = $currentHead;
 					}
 				} else { // HEADs do not match
-					$response["ops"] = Op::getOpsAfterJson($esId, $seqHead);
+					$response["ops"] = $op->getOpsAfterJson($esId, $seqHead);
 					$response["head_seq"] = $currentHead;
 					$response["result"] = $hasOps ? 'conflict' : 'new_ops';
 				}
 				
-				$inactiveMembers = Member::cleanSession($esId);
-				if (is_array($inactiveMembers)){
-					foreach ($inactiveMembers as $member){
-						Op::removeCursor($esId, $member['member_id']);
-					}
+				$inactiveMembers = $member->updateByTimeout($esId);
+				foreach ($inactiveMembers as $inactive){
+					$op->removeCursor($esId, $inactive['member_id']);
 				}
-				
+			
 			} else {
 				// Error - no seq_head passed
 				throw new BadRequestException();
diff --git a/ajax/sessionController.php b/ajax/sessionController.php
index 60cb29c4..907e6fd1 100644
--- a/ajax/sessionController.php
+++ b/ajax/sessionController.php
@@ -30,7 +30,7 @@ class SessionController extends Controller{
 	
 	protected static function join($uid, $file){
 		try{
-			$session = Session::start($uid, $file);
+			$session = Db_Session::start($uid, $file);
 			\OCP\JSON::success($session);
 			exit();
 		} catch (\Exception $e){
@@ -45,8 +45,8 @@ class SessionController extends Controller{
 	 */
 	public static function save(){
 		try {
-			$sessionID = @$_SERVER['HTTP_WEBODF_SESSION_ID'];
-			if (!$sessionID){
+			$esId = @$_SERVER['HTTP_WEBODF_SESSION_ID'];
+			if (!$esId){
 				throw new \Exception('Session id can not be empty');
 			}
 			
@@ -58,12 +58,14 @@ class SessionController extends Controller{
 				throw new \Exception('New conent missing');
 			}
 			
-			$session = Session::getSession($sessionID);
-			if (!$session){
+			$session = new Db_Session();
+			$session->load($esId);
+			
+			if (!$session->hasData()){
 				throw new \Exception('Session does not exist');
 			}
-			
-			$file = new File($session['file_id']);
+			$sessionData = $session->getData();
+			$file = new File($sessionData['file_id']);
 			if (!$file->isPublicShare()){
 				self::preDispatch();
 			} else {
@@ -80,7 +82,7 @@ class SessionController extends Controller{
 			
 			if ($view->file_exists($path)){
 				$currentHash = sha1($view->file_get_contents($path));
-				if ($currentHash !== $session['genesis_hash']){
+				if ($currentHash !== $sessionData['genesis_hash']){
 					// Original file was modified externally. Save to a new one
 					$path = Helper::getNewFileName($view, $path, '-conflict');
 				}
@@ -88,7 +90,7 @@ class SessionController extends Controller{
 			
 			if ($view->file_put_contents($path, $content)){
 				//Document saved successfully. Cleaning session data
-				Session::cleanUp($sessionID);
+				Db_Session::cleanUp($esId);
 			}
 			\OCP\JSON::success();
 			exit();
@@ -105,7 +107,8 @@ class SessionController extends Controller{
 		$info = array();
 
 		if (is_array($items)){
-			$info = Session::getInfoByFileid($items);
+			$session = new Db_Session();
+			$info = $session->getInfoByFileId($items);
 		}
 
 		\OCP\JSON::success(array(
@@ -115,10 +118,8 @@ class SessionController extends Controller{
 	
 	public static function listAll(){
 		self::preDispatch();
-		$sessions = Session::getAll();
-		if (!is_array($sessions)){
-			$sessions = array();
-		}
+		$session = new Db_Session();
+		$sessions = $session->getCollection();
 
 		$preparedSessions = array_map(
 				function($x){
@@ -132,10 +133,8 @@ class SessionController extends Controller{
 
 	public static function listAllHtml(){
 		self::preDispatch();
-		$sessions = Session::getAll();
-		if (!is_array($sessions)){
-			$sessions = array();
-		}
+		$session = new Db_Session();
+		$sessions = $session->getCollection();
 
 		$preparedSessions = array_map(
 				function($x){
diff --git a/appinfo/app.php b/appinfo/app.php
index ac9a54ec..57e842e0 100755
--- a/appinfo/app.php
+++ b/appinfo/app.php
@@ -40,6 +40,9 @@ OC::$CLASSPATH['OCA\Documents\SessionController'] = 'documents/ajax/sessionContr
 OC::$CLASSPATH['OCA\Documents\UserController'] = 'documents/ajax/userController.php';
 OC::$CLASSPATH['OCA\Documents\Download_Simple'] = 'documents/lib/download/simple.php';
 OC::$CLASSPATH['OCA\Documents\Download_Range'] = 'documents/lib/download/range.php';
+OC::$CLASSPATH['OCA\Documents\Db_Session'] = 'documents/lib/db/session.php';
+OC::$CLASSPATH['OCA\Documents\Db_Member'] = 'documents/lib/db/member.php';
+OC::$CLASSPATH['OCA\Documents\Db_Op'] = 'documents/lib/db/op.php';
 
 //Listen to delete file signal
 \OCP\Util::connectHook('OC_Filesystem', 'delete', "OCA\Documents\Storage", "onDelete");
diff --git a/lib/db.php b/lib/db.php
index a40168e9..823b76c8 100644
--- a/lib/db.php
+++ b/lib/db.php
@@ -15,16 +15,189 @@ namespace OCA\Documents;
  * Generic DB class 
  */
 
-class Db {
+abstract class Db {
+	
+	protected $data;
+	
+	protected $tableName;
+	
+	protected $insertStatement;
+	
+	protected $loadStatement;
+	
+	public function __construct($data = array()){
+		$this->setData($data);
+	}
+	
+	/**
+	 * Insert current object data into database
+	 * @return mixed
+	 */
+	public function insert(){
+		$result = $this->execute($this->insertStatement);
+		return $result;
+	}
+	
+	/**
+	 * Get id of the recently inserted record
+	 * @return mixed
+	 */
+	public function getLastInsertId(){
+		return \OCP\DB::insertid($this->tableName);
+	}
+	
+	/**
+	 * Get single record by primary key
+	 * @param type $value primary key value
+	 * @return \OCA\Documents\Db
+	 */
+	public function load($value){
+		if (!is_array($value)){
+			$value = array($value);
+		}
+		
+		$result = $this->execute($this->loadStatement, $value);
+		$data = $result->fetchRow();
+		if (!is_array($data)){
+			$data = array();
+		}
+		$this->data = $data;
+		return $this;
+	}
+	
+	/**
+	 * Get single record matching condition
+	 * @param string $field for WHERE condition
+	 * @param mixed $value matching value(s)
+	 * @return \OCA\Documents\Db
+	 * @throws Exception
+	 */
+	public function loadBy($field, $value){
+		if (!is_array($value)){
+			$value = array($value);
+		}
+		$result = $this->execute('SELECT * FROM ' . $this->tableName . ' WHERE `'. $field .'` =?', $value);
+		$data = $result->fetchAll();
+		if (!is_array($data) || !count($data)){
+			$this->data = array();
+		} elseif (count($data)!=1) {
+			throw new Exception('Duplicate ' . $value . ' for the filed ' . $field);
+		} else {
+			$this->data = $data[0];
+		}
+		
+		return $this;
+	}
+
+	/**
+	 * Delete records matching the condition
+	 * @param string $field for WHERE condition
+	 * @param mixed $value matching value(s)
+	 */
+	public function deleteBy($field, $value){
+		if (!is_array($value)){
+			$value = array($value);
+		}
+		if (count($value)===1){
+			$result = $this->execute('DELETE FROM ' . $this->tableName . ' WHERE `'. $field .'` =?', $value);
+		} else {
+			$stmt = $this->buildInQuery($field, $value);
+			$result = $this->execute('DELETE FROM ' . $this->tableName . ' WHERE ' . $stmt, $value);
+		}
+	}
+	
+	/**
+	 * Get all records from the table
+	 * @return array
+	 */
+	public function getCollection(){
+		$result = $this->execute('SELECT * FROM ' . $this->tableName);
+		$data = $result->fetchAll();
+		if (!is_array($data)){
+			$data = array();
+		}
+		return $data;
+	}
+	
+	/**
+	 * Get array of matching records
+	 * @param string $field for WHERE condition
+	 * @param mixed $value matching value(s)
+	 * @return array
+	 */
+	public function getCollectionBy($field, $value){
+		if (!is_array($value)){
+			$value = array($value);
+		}
+		if (count($value)===1){
+			$result = $this->execute('SELECT * FROM ' . $this->tableName . ' WHERE `'. $field .'` =?', $value);
+		} else {
+			$stmt = $this->buildInQuery($field, $value);
+			$result = $this->execute('SELECT * FROM ' . $this->tableName . ' WHERE '. $stmt , $value);
+		}
+		
+		$data = $result->fetchAll();
+		if (!is_array($data)){
+			$data = array();
+		}
+		return $data;
+	}
+	
+	/**
+	 * Get object data
+	 * @return Array
+	 */
+	public function getData(){
+		return $this->data;
+	}
+	
+	/**
+	 * Set object data
+	 * @param array $data
+	 */
+	public function setData($data){
+		$this->data = $data;
+	}
+	
+	/**
+	 * Check if there are any data in current object
+	 * @return bool 
+	 */
+	public function hasData(){
+		return count($this->data)>0;
+	}
+	
 	/**
 	 * Build placeholders for the query with variable input data 
+	 * @param string $field field name
 	 * @param Array $array data
-	 * @return String string of '?' placeholders matching the number of elements in array
+	 * @return String `field` IN (?, ?...) placeholders matching the number of elements in array
 	 */
-	public static function buildPlaceholders($array){
+	protected function buildInQuery($field, $array){
 		$count = count($array);
 		$placeholders = array_fill(0, $count, '?');
 		$stmt = implode(', ', $placeholders);
-		return $stmt;
+		return '`' . $field . '` IN ('  . $stmt . ')';
+	}
+	
+	/**
+	 * Execute a query on database
+	 * @param string $statement query to be executed
+	 * @param mixed $args value(s) for the query. 
+	 * If omited the query will be run on the current object $data
+	 * @return mixed (array/false)
+	 */
+	protected function execute($statement, $args = null){
+		$query = \OCP\DB::prepare($statement);
+		
+		if (!is_null($args)){
+			$result = $query->execute($args);
+		} elseif (count($this->data)){
+			$result = $query->execute($this->data);
+		} else {
+			$result = $query->execute();
+		}
+		
+		return $result;
 	}
-}
\ No newline at end of file
+}
diff --git a/lib/db/member.php b/lib/db/member.php
new file mode 100644
index 00000000..11d9cd9e
--- /dev/null
+++ b/lib/db/member.php
@@ -0,0 +1,97 @@
+<?php
+
+/**
+ * ownCloud - Documents App
+ *
+ * @author Victor Dubiniuk
+ * @copyright 2013 Victor Dubiniuk victor.dubiniuk@gmail.com
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ */
+
+namespace OCA\Documents;
+
+class Db_Member extends Db{
+
+	const DB_TABLE = '`*PREFIX*documents_member`';
+	
+	const ACTIVITY_THRESHOLD = 60; // 1 Minute
+	
+	const MEMBER_STATUS_ACTIVE = 1;
+	const MEMBER_STATUS_INACTIVE = 2;
+	
+	protected $tableName  = '`*PREFIX*documents_member`';
+
+	protected $insertStatement  = 'INSERT INTO `*PREFIX*documents_member` (`es_id`, `uid`, `color`, `last_activity`)
+			VALUES (?, ?, ?, ?)';
+	
+	protected $loadStatement = 'SELECT * FROM `*PREFIX*documents_member` WHERE `member_id`= ?';
+
+	public function updateActivity($memberId){
+		return $this->execute(
+				'UPDATE ' . $this->tableName . ' SET `last_activity`=?, `status`=? WHERE `member_id`=?',
+				array(
+					time(),
+					self::MEMBER_STATUS_ACTIVE,
+					$memberId
+				)
+		);
+	}
+	
+	/**
+	 * Mark members as inactive
+	 * @param string $esId - session Id
+	 * @return array - list of memberId that were marked as inactive
+	 */
+	public function updateByTimeout($esId){
+		$time = $this->getInactivityPeriod();
+
+		$result = $this->execute('
+			SELECT `member_id`
+			FROM ' . self::DB_TABLE . '
+			WHERE `es_id`= ?
+				AND `last_activity`<?
+				AND `status`=?
+			',
+			array(
+				$esId,
+				$time,
+				self::MEMBER_STATUS_ACTIVE
+			)
+		);
+		
+		$deactivated = $result->fetchAll();
+		if (is_array($deactivated) && count($deactivated)){
+			$deactivated = array_map(
+				function($x){
+					return ($x['member_id']);
+				}, $deactivated
+			);
+			$this->deactivate($deactivated);
+		} else {
+			$deactivated = array();
+		}
+
+		return $deactivated;
+	}
+
+	/**
+	 * Update members to inactive state
+	 * @param array $memberIds
+	 */
+	protected function deactivate($memberIds){
+		$stmt = $this->buildInQuery('member_id', $memberIds);
+		array_unshift($memberIds, self::MEMBER_STATUS_INACTIVE);
+		$this->execute('
+			UPDATE ' . $this->tableName . '
+			SET `status`=?
+			WHERE ' . $stmt,
+			$memberIds
+		);
+	}
+	
+	protected function getInactivityPeriod(){
+		return time() - self::ACTIVITY_THRESHOLD;
+	}
+}
diff --git a/lib/op.php b/lib/db/op.php
similarity index 57%
rename from lib/op.php
rename to lib/db/op.php
index 2ffa582a..5446e382 100644
--- a/lib/op.php
+++ b/lib/db/op.php
@@ -11,40 +11,36 @@
 
 namespace OCA\Documents;
 
-class Op {
+class Db_Op extends Db {
 
 	const DB_TABLE = '`*PREFIX*documents_op`';
 	
-	public static function add($esId, $memberId, $opspec){
-		$query = \OCP\DB::prepare('
-			INSERT INTO ' . self::DB_TABLE . ' (`es_id`, `member`, `opspec`)
-			VALUES (?, ?, ?)
-			');
-		$query->execute(array(
-			$esId,
-			$memberId,
-			$opspec,
-		));
-
-		return \OCP\DB::insertid(self::DB_TABLE);
-	}
+	protected $tableName = '`*PREFIX*documents_op`';
 	
+	protected $insertStatement = 'INSERT INTO `*PREFIX*documents_op` (`es_id`, `member`, `opspec`) VALUES (?, ?, ?)';
+
 	public static function addOpsArray($esId, $memberId, $ops){
 		$lastSeq = "";
+		$opObj = new Db_Op();
 		foreach ($ops as $op) {
-			$lastSeq = self::add($esId, $memberId, json_encode($op));
+			$opObj->setData(array(
+				$esId, 
+				$memberId, 
+				json_encode($op)
+			));
+			$opObj->insert();
+			$lastSeq = $opObj->getLastInsertId();
 		}
 		return $lastSeq;
 	}
-
-
+	
 	/**
 	 * @returns "" when there are no Ops, or the seq of the last Op
 	 */
-	public static function getHeadSeq($esId){
+	public function getHeadSeq($esId){
 		$query = \OCP\DB::prepare('
 			SELECT `seq`
-			FROM ' . self::DB_TABLE . '
+			FROM ' . $this->tableName . '
 			WHERE `es_id`=?
 			ORDER BY `seq` DESC
 			', 1);
@@ -56,8 +52,8 @@ class Op {
 		return !$result ? "" : $result;
 	}
 	
-	public static function getOpsAfterJson($esId, $seq){
-		$ops = self::getOpsAfter($esId, $seq);
+	public function getOpsAfterJson($esId, $seq){
+		$ops = $this->getOpsAfter($esId, $seq);
 		if (!is_array($ops)){
 			$ops = array();
 		}
@@ -72,7 +68,7 @@ class Op {
 		return $ops;
 	}
 	
-	public static function getOpsAfter($esId, $seq){
+	public function getOpsAfter($esId, $seq){
 		if ($seq == ""){
 			$seq = -1;
 		}
@@ -86,18 +82,13 @@ class Op {
 		$result = $query->execute(array($esId, $seq));
 		return $result->fetchAll();
 	}
-	
-	public static function deleteBySessionId($esId){
-		$query = \OCP\DB::prepare('DELETE FROM ' . self::DB_TABLE . ' WHERE `es_id` = ?');
-		$query->execute(array($esId));
-	}
 
-	public static function removeCursor($esId, $memberId){
-		return self::add(
-				$esId, 
-				0,
-				'{"optype":"RemoveCursor","memberid":"'. $memberId .'","reason":"server-idle","timestamp":'. time() .'}'
-		);
+	public function removeCursor($esId, $memberId){
+		$op = new Db_Op(array(
+			$esId, 
+			0,
+			'{"optype":"RemoveCursor","memberid":"'. $memberId .'","reason":"server-idle","timestamp":'. time() .'}'
+		));
+		$op->insert();
 	}
-
 }
diff --git a/lib/db/session.php b/lib/db/session.php
new file mode 100644
index 00000000..d6d79385
--- /dev/null
+++ b/lib/db/session.php
@@ -0,0 +1,163 @@
+<?php
+
+/**
+ * ownCloud - Documents App
+ *
+ * @author Victor Dubiniuk
+ * @copyright 2013 Victor Dubiniuk victor.dubiniuk@gmail.com
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ */
+
+namespace OCA\Documents;
+
+/**
+ *  Session management 
+ */
+class Db_Session extends \OCA\Documents\Db {
+
+	/**
+	 * DB table
+	 */
+	const DB_TABLE = '`*PREFIX*documents_session`';
+	protected $tableName  = '`*PREFIX*documents_session`';
+
+	protected $insertStatement  = 'INSERT INTO `*PREFIX*documents_session` (`es_id`, `genesis_url`, `genesis_hash`, `owner`, `file_id`)
+			VALUES (?, ?, ?, ?, ?)';
+	
+	protected $loadStatement = 'SELECT * FROM `*PREFIX*documents_session` WHERE `es_id`= ?';
+
+	/**
+	 * Start a editing session or return an existing one
+	 * @param string $uid of the user starting a session
+	 * @param \OCA\Documents\File $file - file object
+	 * @return array
+	 * @throws \Exception
+	 */
+	public static function start($uid, File $file){
+		list($ownerView, $path) = $file->getOwnerViewAndPath();
+		
+		$oldSession = new Db_Session();
+		$oldSession->loadBy('file_id', $file->getFileId());
+
+		//If there is no existing session we need to start a new one
+		if (!$oldSession->hasData()){
+
+			//TODO: check if genesis document is a valid odt
+			$genesisPath = $ownerView->storeDocument($ownerView, $path);
+			if (!$genesisPath){
+				throw new \Exception('Unable to copy document. Check permissions and make sure you have enought free space.');
+			}
+
+			$hash = $ownerView->getHashByGenesis($genesisPath);
+			
+			$newSession = new Db_Session(array(
+				$genesisPath, $hash, $file->getOwner(), $file->getFileId()
+			));
+			
+			if (!$newSession->insert()){
+				throw new \Exception('Failed to add session into database');
+			}
+		}
+		
+		$session = $oldSession
+					->loadBy('file_id', $file->getFileId())
+					->getData()
+				;
+		
+		$member = new Db_Member(array(
+			$session['es_id'], 
+			$uid, 
+			Helper::getRandomColor()
+		));
+		if ($member->insert()){
+			$session['member_id'] = (string) $member->getLastInsertId();
+		} else {
+			throw new \Exception('Failed to add member into database');
+		}
+		
+		$session['permissions'] = $ownerView->getFilePermissions($path);
+		
+		return $session;
+	}
+	
+	public static function cleanUp($esId){
+		$session = new Db_Session();
+		$session->deleteBy('es_id', $esId);
+		
+		$member = new Db_Member();
+		$member->deleteBy('es_id', $esId);
+		
+		$op= new Db_Op();
+		$op->deleteBy('es_id', $esId);
+	}
+	
+	public function insert(){
+		$esId = $this->getUniqueSessionId();
+		array_unshift($this->data, $esId);
+		return parent::insert($this->data);
+	}
+
+	public function getInfo($esId){
+		$result = $this->execute('
+			SELECT `s`.*, COUNT(`m`.`member_id`) AS `users`
+			FROM ' . $this->tableName . ' AS `s`
+			LEFT JOIN `*PREFIX*documents_member` AS `m` ON `s`.`es_id`=`m`.`es_id`
+				AND `m`.`status`=' . Db_Member::MEMBER_STATUS_ACTIVE . '
+				AND `m`.`uid` != ?
+			WHERE `s`.`es_id` = ?
+			GROUP BY `m`.`es_id`
+			',
+			array(
+					\OCP\User::getUser(),
+					$esId
+			)
+		);
+
+		$info = $result->fetchRow();
+		if (!is_array($info)){
+			$info = array();
+		}
+		return $info;
+	}
+
+	public function getInfoByFileId($fileIds){
+		if (!is_array($fileIds)){
+			return array();
+		}
+
+		$stmt = $this->buildInQuery('file_id', $fileIds);
+
+		$result = $this->execute('
+			SELECT `s`.*, COUNT(`m`.`member_id`) AS `users`
+			FROM ' . $this->tableName . ' AS `s`
+			LEFT JOIN `*PREFIX*documents_member` AS `m` ON `s`.`es_id`=`m`.`es_id`
+				AND `m`.`status`=' . Db_Member::MEMBER_STATUS_ACTIVE . '
+			WHERE `s`.`file_id` ' . $stmt .'
+			GROUP BY `m`.`es_id`',
+			$fileIds
+		);
+
+		$info = $result->fetchAll();
+		if (!is_array($info)){
+			$info = array();
+		}
+		return $info;
+	}
+
+	protected function getUniqueSessionId(){
+		$testSession = new Db_Session();
+		do{
+			// this prevents branching for stable5 for now:
+			// OC_Util::generate_random_bytes was camelCased
+			if (method_exists('\OC_Util', 'generate_random_bytes')){
+				$id = \OC_Util::generate_random_bytes(30);
+			} else {
+				$id = \OC_Util::generateRandomBytes(30);
+			}
+		}while ($testSession->load($id)->hasData());
+
+		return $id;
+	}
+}
diff --git a/lib/member.php b/lib/member.php
deleted file mode 100644
index 8970f1b8..00000000
--- a/lib/member.php
+++ /dev/null
@@ -1,133 +0,0 @@
-<?php
-
-/**
- * ownCloud - Documents App
- *
- * @author Victor Dubiniuk
- * @copyright 2013 Victor Dubiniuk victor.dubiniuk@gmail.com
- *
- * This file is licensed under the Affero General Public License version 3 or
- * later.
- */
-
-namespace OCA\Documents;
-
-class Member extends Db{
-
-	const DB_TABLE = '`*PREFIX*documents_member`';
-	
-	const ACTIVITY_THRESHOLD = 60; // 10 Minutes
-	
-	const MEMBER_STATUS_ACTIVE = 1;
-	const MEMBER_STATUS_INACTIVE = 2;
-
-	public static function add($esId, $uid, $color){
-		$query = \OCP\DB::prepare('
-			INSERT INTO ' . self::DB_TABLE . ' (`es_id`, `uid`, `color`, `last_activity`)
-			VALUES (?, ?, ?, ?)
-			');
-		$query->execute(array(
-			$esId,
-			$uid,
-			$color,
-			time()
-		));
-
-		return \OCP\DB::insertid(self::DB_TABLE);
-	}
-
-	public static function getMember($id){
-		$query = \OCP\DB::prepare('SELECT * FROM ' . self::DB_TABLE . ' WHERE `member_id`= ?');
-		$result = $query->execute(array($id));
-		return $result->fetchRow();
-	}
-
-	public static function getMembersAsArray($ids){
-		$memberCount = count($ids);
-		if (!$memberCount || !is_array($ids)){
-			return array();
-		}
-		
-		$stmt = self::buildPlaceholders($ids);
-		$query = \OCP\DB::prepare('SELECT * FROM ' . self::DB_TABLE . ' WHERE `member_id` IN (' . $stmt . ')');
-		$result = $query->execute($ids);
-		return $result->fetchAll();
-	}
-	
-	public static function updateMemberActivity($memberId){
-		$query = \OCP\DB::prepare('UPDATE ' . self::DB_TABLE . ' SET `last_activity`=?, `status`=? WHERE `member_id`=?');
-		$query->execute(array(
-			time(),
-			self::MEMBER_STATUS_ACTIVE,
-			$memberId
-		));
-	}
-
-	public static function getMembersByEsId($esId, $lastActivity = null){
-		if (is_null($lastActivity)){
-			$activeSince = self::getInactivityPeriod();
-		} else {
-			$activeSince = $lastActivity;
-		}
-
-		$query = \OCP\DB::prepare('SELECT * FROM ' . self::DB_TABLE . ' WHERE `es_id`= ? AND `last_activity` > ?');
-		$result = $query->execute(array($esId, $activeSince));
-		return $result->fetchAll();
-	}
-	
-	/**
-	 * Mark memebers as inactive
-	 * @param string $esId - session Id
-	 * @return array - list of memberId that were marked as inactive
-	 */
-	public static function cleanSession($esId){
-		$time = self::getInactivityPeriod();
-
-		$query = \OCP\DB::prepare('
-			SELECT `member_id`
-			FROM ' . self::DB_TABLE . '
-			WHERE `es_id`= ?
-				AND `last_activity`<?
-				AND `status`=?
-			');
-		$result = $query->execute(array(
-				$esId,
-				$time,
-				self::MEMBER_STATUS_ACTIVE
-		));
-		$deactivated = $result->fetchAll();
-		
-		self::deactivate($esId, $time);
-
-		return $deactivated;
-	}
-
-	/**
-	 * Update members to inactive state
-	 * @param string $esId
-	 * @param timestamp $time
-	 */
-	protected static function deactivate($esId, $time){
-		$query = \OCP\DB::prepare('
-			UPDATE ' . self::DB_TABLE . '
-			SET `status`=?
-			WHERE `es_id`=?
-				AND `last_activity`<?
-			');
-		$query->execute(array(
-			self::MEMBER_STATUS_INACTIVE,
-			$esId,
-			$time
-		));
-	}
-	
-	public static function deleteBySessionId($esId){
-		$query = \OCP\DB::prepare('DELETE FROM ' . self::DB_TABLE . ' WHERE `es_id` = ?');
-		$query->execute(array($esId));
-	}
-	
-	protected static function getInactivityPeriod(){
-		return time() - self::ACTIVITY_THRESHOLD;
-	}
-
-}
diff --git a/lib/session.php b/lib/session.php
deleted file mode 100644
index a03aa14f..00000000
--- a/lib/session.php
+++ /dev/null
@@ -1,183 +0,0 @@
-<?php
-
-/**
- * ownCloud - Documents App
- *
- * @author Victor Dubiniuk
- * @copyright 2013 Victor Dubiniuk victor.dubiniuk@gmail.com
- *
- * This file is licensed under the Affero General Public License version 3 or
- * later.
- */
-
-namespace OCA\Documents;
-
-class Session extends Db {
-
-	const DB_TABLE = '`*PREFIX*documents_session`';
-
-	public static function start($uid, File $file){
-		list($ownerView, $path) = $file->getOwnerViewAndPath();
-		$session = Session::getSessionByFileId( $file->getFileId() );
-
-		//If there is no existing session we need to start a new one
-		if (!$session || empty($session)){
-
-			$genesisPath = $ownerView->storeDocument($ownerView, $path);
-
-			if (!$genesisPath){
-				throw new \Exception('Unable to copy document. Check permissions and make sure you have enought free space.');
-			}
-
-			$hash = $ownerView->getHashByGenesis($genesisPath);
-			$session = Session::add(
-				$genesisPath, $hash, $file->getOwner(), $file->getFileId()
-			);
-		}
-
-		$session['permissions'] = $ownerView->getFilePermissions($path);
-		$session['member_id'] = (string) Member::add($session['es_id'], $uid, Helper::getRandomColor());
-		
-		return $session;
-	}
-
-	public static function add($genesis, $hash, $owner, $fileId){
-		$query = \OCP\DB::prepare('
-			INSERT INTO ' . self::DB_TABLE . ' (`es_id`, `genesis_url`, `genesis_hash`, `owner`, `file_id`)
-			VALUES (?, ?, ?, ?, ?)
-			');
-
-		$data = array(
-			'es_id' => self::getUniqueSessionId(),
-			'genesis_url' => $genesis,
-			'genesis_hash' => $hash,
-			'owner' => $owner,
-			'file_id' => $fileId
-		);
-		$result = $query->execute(array_values($data));
-
-		if ($result){
-			return $data;
-		}
-
-		return false;
-	}
-
-	public static function getAll(){
-		$query = \OCP\DB::prepare('SELECT * FROM ' . self::DB_TABLE);
-		$result = $query->execute();
-		return $result->fetchAll();
-	}
-
-	public static function getSession($id){
-		$query = \OCP\DB::prepare('SELECT * FROM ' . self::DB_TABLE . ' WHERE `es_id`= ?');
-		$result = $query->execute(array($id));
-		return $result->fetchRow();
-	}
-
-	public static function getInfo($esId){
-
-		$query = \OCP\DB::prepare('
-			SELECT `s`.*, COUNT(`m`.`member_id`) AS `users`
-			FROM ' . self::DB_TABLE . ' AS `s`
-			LEFT JOIN `*PREFIX*documents_member` AS `m` ON `s`.`es_id`=`m`.`es_id`
-				AND `m`.`status`=' . Member::MEMBER_STATUS_ACTIVE . '
-				AND `m`.`uid` != ?
-			WHERE `s`.`es_id` = ?
-			GROUP BY `m`.`es_id`
-			');
-		$result = $query->execute(
-				array(
-					\OCP\User::getUser(),
-					$esId
-				)
-		);
-
-		$info = $result->fetchRow();
-		if (!is_array($info)){
-			$info = array();
-		}
-		return $info;
-	}
-
-	public static function getSessionByFileId($fileId){
-		$sessions = self::getSessionsByFileIds(array($fileId));
-		if (count($sessions) > 1){
-			Helper::errorLog('documents', 'more than one session found for file id ' . $fileId);
-		}
-
-		if (count($sessions)){
-			return $sessions[0];
-		}
-
-		return null;
-	}
-
-	public static function getSessionsByFileIds($fileIds){
-		if (!is_array($fileIds)){
-			$fileIds = array($fileIds);
-		}
-
-		$stmt = self::buildPlaceholders($fileIds);
-		$query = \OCP\DB::prepare('SELECT * FROM ' . self::DB_TABLE . ' WHERE `file_id` IN (' . $stmt . ')');
-		$result = $query->execute($fileIds);
-		$sessions = $result->fetchAll();
-		if (!is_array($sessions)){
-			$sessions = array();
-		}
-		return $sessions;
-	}
-
-	public static function getInfoByFileid($fileIds){
-		if (!is_array($fileIds)){
-			return array();
-		}
-
-		$stmt = self::buildPlaceholders($fileIds);
-		if (!$stmt){
-			return array();
-		}
-
-		$query = \OCP\DB::prepare('
-			SELECT `s`.*, COUNT(`m`.`member_id`) AS `users`
-			FROM ' . self::DB_TABLE . ' AS `s`
-			LEFT JOIN `*PREFIX*documents_member` AS `m` ON `s`.`es_id`=`m`.`es_id`
-				AND `m`.`status`=' . Member::MEMBER_STATUS_ACTIVE . '
-			WHERE `s`.`file_id` IN (' . $stmt . ')
-			GROUP BY `m`.`es_id`
-			');
-		$result = $query->execute($fileIds);
-
-		$info = $result->fetchAll();
-		if (!is_array($info)){
-			$info = array();
-		}
-		return $info;
-	}
-
-	public static function cleanUp($esId){
-		self::delete($esId);
-		Member::deleteBySessionId($esId);
-		Op::deleteBySessionId($esId);
-	}
-
-	public static function delete($esId){
-		$query = \OCP\DB::prepare('DELETE FROM ' . self::DB_TABLE . ' WHERE `es_id` = ?');
-		$query->execute(array($esId));
-	}
-
-	protected static function getUniqueSessionId(){
-		do{
-			// this prevents branching for stable5 for now:
-			// OC_Util::generate_random_bytes was camelCased
-			if (method_exists('\OC_Util', 'generate_random_bytes')){
-				$id = \OC_Util::generate_random_bytes(30);
-			} else {
-				$id = \OC_Util::generateRandomBytes(30);
-			}
-		}while (self::getSession($id));
-
-		return $id;
-	}
-
-}
diff --git a/lib/storage.php b/lib/storage.php
index ec1c6cab..9e6d63a1 100755
--- a/lib/storage.php
+++ b/lib/storage.php
@@ -56,11 +56,16 @@ class Storage {
 			return;
 		}
 		
-		$session = Session::getSessionByFileId($fileId);
+		$sessionObj = new Db_Session();
+		$session = $sessionObj
+					->loadBy('file_id', $fileId)
+					->getData()
+				;
+
 		if (!is_array($session)){
 			return;
 		}
 		
-		Session::cleanUp($session['es_id']);
+		Db_Session::cleanUp($session['es_id']);
 	}
 }