Kristian Nielsen via developers <developers@lists.mariadb.org> writes:
If you want to give a warning for these functions, then you need to create an SQL mode or some other handle for the DBA to disable the warning and keep their application running. And the warning should explain why it's there,
Ah, we have --old-mode for this purpose. So add a new mode for --old-mode that disables the warning for the ENCODE/DECODE functions. And later that mode could re-enable the functions, if you want to disable them by default after deprecation period. The new mode could be specific to the ENCODE/DECODE functions (COMPAT_ENCODE_DECODE perhaps), or it could be generic for features whose use is discouraged (eg. COMPAT_DISCOURAGED). I'd suggest the latter to simplify the life of DBAs maintaining legacy applications, but I don't have a strong opinion one way or the other, nor for the exact naming. - Kristian.