code: function (arr) {
  
  	// extract collection name
  	if (arr && typeof arr._name === 'string') {
  
  		var size = arr.length - arr._index;
  
  		if (size <= 0)
  			return false;
  		
  		LOG.sys('try to store to array [' + arr._name + '], # of elements to store: ' + size, 'SR.Sync');
  				
  		// TODO: wasteful of space?
  		// NOTE: only new array entries will be stored to DB
  		var elements = [];
  		for (var i=arr._index; i < arr.length; i++)
  			elements.push(arr[i]);
  
  		// update index count (regardless of update success or not?)
  		arr._index = arr.length;
  		
  		// TODO: find right way to store
  		// store away
  		// NOTE: $each is used here (try to hide it?)
  		SR.DB.updateArray(SR.Settings.DB_NAME_SYNC, {name: arr._name}, {data: elements},
  			function (result) {
  				LOG.sys('update array success: ' + result, 'SR.Sync');
  			}, 
  			function (result) {
  				LOG.error('update array fail: ' + result, 'SR.Sync');
  			}
  		);
  		return true;
  	}
  	else
  		LOG.error('cannot store to DB, arr_name unavailable', 'SR.Sync');
  		
  	return false;
  }
docs: store a particular record to DB