[cap-talk] Styles of persistance

[Ludovic Courtès]

Hi,

Bill Frantz <frantz at pwpconsult.com> writes:

> I assume in-band means you call the object and ask it to install an
> upgrade to itself. That technique has the unfortunate effect of
> requiring preplanning on the part of the programmer, adding to my
> contention that these systems offer a choice between easy
> persistence and easy upgrade.

CLOS and derivative object systems often provide a `change-class' method
as part of their meta-object protocol (MOP).  Specializing this method
allows the "translation" or "upgrade" of an object from one class to
another to be described.

Maybe a source of inspiration for the design of upgrade mechanisms for
orthogonally-persistent systems?

Thanks,
Ludovic.