What's a POS??
Kelly Murray
kem@Franz.COM
Sat, 10 May 1997 15:29:10 -0700
Let me say how AllegroStore works.
1. It has both transient and persistent memory, everything is transient
by default.
2. It has a metaclass, persistent-standard-class, which is used to
define a class to have persistent instances.
e.g. (defclass persistent-foo () (..) (:metaclass persistent-standard-class))
3. Only CLOS instances of persistent-standard-class are persistent.
3.5 Code runs the same on both persistent and transient instances.
4. The slot values of a persistent instance are also persistent.
5. Writing a transient value into the slot of a persistent instance
makes it persistent.
6. All persistent instances are invalid unless a transaction is active
My idea is slightly different, and still under development,
but one difference is I think all class instances
should be able to be persistent by having them
be pointed to by existing persistent objects,
or by explicitly calling (make-persistent obj) on the instance.
-Kelly Edward Murray