Hi,
>> [ concerning handling a change in a single datatype's representation ]
>
>> 1. Under old system, munge the system catalog to add code for new inet
>> type with new OID. Probably needs a shared lib (if you could create
>> type input/output function with pl/pgsql it would help here).
>> 2. Execute ALTER COLUMN TYPE USING to switch to the new type.
>> 3. Shutdown old server
>> 4. Complete catalog changes
>> 5. Startup new version
>
> Probably easier and more flexible just to include both versions of the
> datatype in the new release, and tell people they'd better ALTER COLUMN
> TYPE sometime before updating to release N+2.
Sounds very nice to have for me! Add an easy way to see which columns are
still in the old format, and upgrading will be so much easier.
- Sander