title: why greenplum can not create same table name in different schema
body: <p>I want create same external table in greenplum in different schema ,but it turns out ERROR:  relation "my_external_table_name" already exists</p>
  
  <p><a href="http://i.stack.imgur.com/6GlkS.png" rel="nofollow">click check the picture: this is before create external table</a></p>
  
  <p><a href="http://i.stack.imgur.com/DXxo9.png" rel="nofollow">click check the picture: this is after create table</a></p>
  
  <p>Why my previous table disappear?</p>