title: python cx_Oracle connect Remote error
body: <p>i would like to connect to remote <code>oracle database</code> with python and try to create a pandas dataframe:</p>
  
  <pre><code>con = ora.connect('user/pass@remote_ip/XE')
  query = "select * from my_table"
  
  df = pd.read_sql(query, con)
  </code></pre>
  
  <p>I'm using macOS high siera and this is how my host file looks like:</p>
  
  <pre><code>##
  # Host Database
  #
  # localhost is used to configure the loopback interface
  # when the system is booting.  Do not change this entry.
  ##
  127.0.0.1       localhost local
  127.0.0.1 localhost localhost.localdomain local lynx
  255.255.255.255 broadcasthost
  ::1             localhost
  127.0.0.1     activate.adobe.com
  127.0.0.1     practivate.adobe.com
  127.0.0.1     hlrcv.stage.adobe.com
  127.0.0.1     na1r.services.adobe.com
  127.0.0.1 quickplayer.tvgo.hu
  80.211.194.173 anton
  10.2.94.217 lynx
  </code></pre>
  
  <p>I got <code>cx_Oracle.DatabaseError: ORA-21561: OID generation failed</code> error. </p>
  
  <p>If i try from Ubuntu it's working. </p>
  
  <p>My Database version:</p>
  
  <pre><code>Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
  PL/SQL Release 11.2.0.2.0 - Production
  CORE     11.2.0.2.0            Production
  TNS for Linux: Version 11.2.0.2.0 - Production
  NLSRTL Version 11.2.0.2.0 - Production
  </code></pre>
  
  <p>What should I try?</p>