Connections to SQL Anywhere can be made through the TDS protocol (Open Client and jConnect JDBC connections) or through the SQL Anywhere protocol (ODBC and embedded SQL).
If you have users who use both TDS and the SQL Anywhere-specific protocol, you can configure their initial settings using stored procedures. As it is shipped, SQL Anywhere uses this method to set Open Client connections and jConnect connections to reflect default Adaptive Server Enterprise behavior.
The initial settings are controlled using the login_procedure option. This option names a stored procedure to run when users connect. The default setting is to use the sp_login_environment system procedure. You can change this behavior as necessary.
In turn, sp_login_environment checks to see if the connection is being made over TDS. If it is, it calls the sp_tsql_environment procedure, which sets several options to new default values for the current connection.