title: sqlalchemy.exc.IdentifierError: Identifier 'index name' exceeds maximum length of 63 characters
body: <p>I am running a migration script from MYSQL database to PostgreSQL. A new relationship has been recently created on MYSQL which breaks the import to PostgreSQL.</p>
  
  <p>Error: <code>sqlalchemy.exc.IdentifierError: Identifier 'index name' exceeds maximum length of 63 characters</code></p>
  
  <p>Is there a way to truncate the identifier name or alternatively increase the maximum characters limit label length (table name, column name, index) in PostgreSQL to by-pass this limitation?</p>
  
  <p>I found this excerpt from the postgresql documention:</p>
  
  <p><code>The system uses no more than NAMEDATALEN-1 bytes of an identifier; longer names can be written in commands, but they will be truncated. By default, NAMEDATALEN is 64 so the maximum identifier length is 63 bytes. If this limit is problematic, it can be raised by changing the NAMEDATALEN constant in src/include/pg_config_manual.h.</code></p>
  
  <p>Has anyone tried it out? Is there a better solution? I'm using sqlalchemy and python, is there a way of truncating the identifier in Sqlaclchemy?</p>