On Adaptive Server 15.0.3 ESD #1 and later, you can enable compatibility mode at the session or server-wide level:
Session level – use set compatibility_mode on | off to enable or disable compatibility mode for the current session.
Server-wide – use sp_configure 'enable compatibility mode', 1 | 0 to enable or disable compatibility mode for the server.
Setting compatibility mode at the session level takes precedence over the server level.
enable compatibility mode is a dynamic configuration parameter; you need not restart Adaptive Server for it to take effect. However, you must remove any compiled plans for stored procedures, or ad hoc queries, from the statement cache.
sp_configure generates warnings
to indicate that enabling compatibility mode does not affect cached query
plans that are already in the procedure or statement cache.
sp_configure also generates warnings if it detects configuration options that conflict with compatibility mode, such as:
One of abstract plan dump, abstract plan load or abstract plan replace is set.
statement cache and literal autoparam are set.
The histogram tuning factor is set to a value other than 1.
