Setting the value of the LOGIN_MODE option for a given database to Mixed (deprecated) or Integrated using the following SQL statement permanently enables integrated logins for that database.
SET OPTION Public.LOGIN_MODE = Mixed
If the database is shut down and restarted, the option value remains the same and integrated logins are still enabled.
Changing the LOGIN_MODE option temporarily will still allow user access via integrated logins. The following statement will change the option value temporarily:
SET TEMPORARY OPTION "Public".LOGIN_MODE = Mixed
If the permanent option value is Standard, the database will revert to that value when it is shut down.
Setting temporary public options can be considered an additional security measure for database access since enabling integrated logins means that the database is relying on the security of the operating system on which it is running. If the database is shut down and copied to another machine (such as a user's machine) access to the database reverts to the SAP Sybase IQ security model and not the security model of the operating system of the machine where the database has been copied.
See Reference: Statements and Options > SQL Statements > SET OPTION Statement.