code: function readJointsSinceMci(mci, handleJoint, onDone){
  	db.query(
  		"SELECT units.unit FROM units LEFT JOIN archived_joints USING(unit) \n\
  		WHERE (is_stable=0 AND main_chain_index>=? OR main_chain_index IS NULL OR is_free=1) AND archived_joints.unit IS NULL \n\
  		ORDER BY +level", 
  		[mci], 
  		function(rows){
  			async.eachSeries(
  				rows, 
  				function(row, cb){
  					storage.readJoint(db, row.unit, {
  						ifNotFound: function(){
  						//	throw Error("unit "+row.unit+" not found");
  							breadcrumbs.add("unit "+row.unit+" not found");
  							cb();
  						},
  						ifFound: function(objJoint){
  							handleJoint(objJoint);
  							cb();
  						}
  					});
  				},
  				onDone
  			);
  		}
  	);
  }
docs: handleJoint is called for every joint younger than mci