[elephant-devel] Safe to change definition of a persistent class?

[Ben]

Adding and removing slots should be safe.  There is 1 entry per slot
per instance.  Non-existent entries are the same as "unbound slots."
So adding a new slot will make existing instances have unbound slots.
Removing a slot doesn't do anything, it just leaves cruft in the DB.

There are certain rules about changing a slot from transient to
persistent and vice versa -- I think they're laid out in the tutorial.

take care, B

On Mon, 17 Jan 2005, Stefan Scholl wrote:

> Hi!
>
> Is it safe to change the definition of a persistant class which already had 
> some serialized instances at some other time?
>
> Given some objects got written to the store and you change the class in the 
> further development process (reevaluation defclass, rereading changed source, 
> etc.) of your project. Will the data be crippled? Just right by coincidence? 
> Or no problem at all (as long as you just add or remove slots)?
>
>
> Regards,
> Stefan
>
>
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