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.. _glossary:
Glossary
========
.. glossary::
:sorted:
data manager
The object responsible for storing and loading an object's
:term:`pickled data` in a backing store. Also called a :term:`jar`.
jar
Alias for :term:`data manager`: short for "pickle jar", because
it traditionally holds the :term:`pickled data` of persistent objects.
object cache
An MRU cache for objects associated with a given :term:`data manager`.
ghost
An object whose :term:`pickled data` has not yet been loaded from its
:term:`jar`. Accessing or mutating any of its attributes causes
that data to be loaded, which is referred to as :term:`activation`.
volatile attribute
Attributes of a persistent object which are *not* captured as part
of its :term:`pickled data`. These attributes thus disappear during
:term:`deactivation` or :term:`invalidation`.
pickled data
The serialized data of a persistent object, stored in and retrieved
from a backing store by a :term:`data manager`.
activation
Moving an object from the ``GHOST`` state to the ``UPTODATE`` state,
load its :term:`pickled data` from its :term:`jar`.
deactivation
Moving an object from the ``UPTODATE`` state to the ``GHOST`` state,
discarding its :term:`pickled data`.
invalidation
Moving an object from either the ``UPTODATE`` state or the ``CHANGED``
state to the ``GHOST`` state, discarding its :term:`pickled data`.
object id
The stable identifier that uniquely names a particular object.
This is analogous to Python's `id`, but unlike `id`, object
ids remain the same for a given object across different
processes.
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