Hi Marc,
My best guess is weeks, not months. We're hoping for April sometime,
but it depends on a number of factors. Elephant is getting quite
complex to test so the last few bugs can take some time.
You can speed this process up if you want to help develop and test the
association facility (most of the hooks are there so it shouldn't be
too hard, even if you don't fully understand the elephant internals).
If not, we have plenty of new features that need tests written against
them!
Ian
On Mar 18, 2008, at 12:50 AM, Marc wrote:
Ian Eslick wrote:
The pset is probably your best bet. Other collection objects have
more performance impact. With a pset you can ask:
is X a friend of Y? (find-item X (friends Y)) => X | nil
all people that X is friends of:
(remove-nulls
(map-class 'people (lambda (y)
(when (find-item X (friends Y))
Y))
:collect t))
This requires walking all person objects. For larger DB's, you can
build your own 'many-to-many' relation table or waiting for the
next release which should do this for you.
Is there a time line (however preliminary) when this release might be
available?
(defpclass friend-relation ()
((first :accessor first :initarg :first :index t)
(second :accessor second :initarg :second :index t)))
(defmethod add-friend-relation (x y)
(make-instance 'friend-relation :first x :second y))
(defmethod friends-of (x)
(union (mapcar #'second (get-instances-by-slot 'friend-relation
'first x))
(mapcar #'first (get-instances-by-slot 'friend-relation
'second x))))
Of course there are ways to do this more efficiently, but I think
this is the idea.
Many thanks for this guidance. That does, indeed, give me an idea of
the
best way forward in our application.
Best regards,
Marc
On Mar 16, 2008, at 11:06 PM, Marc wrote:
Hello!
I fear that this may be a rather stupid newbie question, but
neither from the documentation nor from the mailing list posts I
got an idea as to the best practice for the following type of
searches. Let's use an example akin to the one in the tutorial:
(defpclass person ()
((name :accessor name :index t)
(friends :accessor friends)) ;collection with names (say as
strings) of the friends of this person
)
Given a similar structure, what is the recommended way to handle
queries of the type "find all persons that X is a friend
of?" (i.e. queries on individual entries in slots that contain
collections)? What would be the best data structure for the
friends slot, assuming that the collection remains fairly stable
over time (psets, lists or other collections)?
Thanks in advance for any hint!
Best regards,
Marc
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