title: sqlalchemy OperationalError: (OperationalError) unable to open database file None None
body: <p>I am trying to create a database in a remote system.The relevant code is given below</p>
  
  <pre><code>log = core.getLogger()
  
  engine = create_engine('sqlite:////name:pass@192.168.129.139/tmp/nwtopology.db',echo=False)
  Base = declarative_base()
  Session = sessionmaker(bind=engine)
  session = Session()
  
  class SourcetoPort(Base):
      """"""
      __tablename__ = 'source_to_port'
      id = Column(Integer, primary_key=True)
      port_no        = Column(Integer)
      src_address    = Column(String,index=True)
  
      #-----------------------------------------
      def __init__(self, src_address,port_no):
          """"""
          self.src_address = src_address
          self.port_no     = port_no
  </code></pre>
  
  <p>Obviously I am trying to create the database in a remote system. I am getting the error:</p>
  
  <pre><code>OperationalError: (OperationalError) unable to open database file None None
  </code></pre>
  
  <p>My questions are as follows.</p>
  
  <p>1) the user that is running the program on local machine is not the same as the user that is trying to create the database on the remote machine.Is this an issue?</p>
  
  <p>2) Are there any mechanisms to improve the latency of inserting an entry into the database and querying and entry by creating a local cached copy?</p>
  
  <p>Regards,
  Karthik.</p>