code: public static void initializeSystem(Transaction tx) {
  		tx.recoveryMgr().recoverSystem(tx);
  		tx.bufferMgr().flushAll();
  		VanillaDb.logMgr().removeAndCreateNewLog();
  		
  		// Add a start record for this transaction
  		new StartRecord(tx.getTransactionNumber()).writeToLog();
  	}
docs: Goes through the log, rolling back all uncompleted transactions. Flushes
  all modified blocks. Finally, writes a quiescent checkpoint record to the
  log and flush it. This method should be called only during system
  startup, before user transactions begin.
  
  @param tx
  the context of executing transaction