ASA Database Administration Guide
Using the Built-in Web Server
By default, character set conversion is performed automatically on outgoing result sets of type text. Result sets of other types, such as binary objects, are not translated. The character set of the request is converted to the database character set, and the result set is converted from the database character set tot he client character set, as required, except on binary columns in the result set. When the request lists multiple character sets that it can handle, the engine takes the first suitable one from the list.
Character-set conversion can be enabled or disabled by setting the HTTP option CharsetConversion. The allowed values are ON and OFF. The default value is ON. The following statement turns automatic character-set conversion off:
call dbo.sa_set_http_option( 'CharsetConversion', 'OFF' )
For more information about built-in stored procedures, see System and catalog stored procedures.