Re: db Model and EOModel
Re: db Model and EOModel
- Subject: Re: db Model and EOModel
- From: Jean-François Veillette <email@hidden>
- Date: Sun, 23 Mar 2008 08:47:13 -0400
First: most problems I have to solve (actually almost all of them) do
not imply concurrent write access to a single object ... so I think I
only needed it once (or very few times).
Talking about rules of thumbs ...
- If you really need to avoid overwriting changes made by others,
optimistic locking might not be enough anyway (the padlock on the
eoattribute). You still need to handle the fact that eof will update
your ec with changes made in another ec (after that ec have
saved). ... EOF was designed with a single user application model
(Openstep-EOF app at the time), unfortunately this model,
unchanged, have deficiencies once applied to a multi-user
application paradigm (how we use it in WO nowadays).
<rant>Fix the design first (that's not to say that the implementation
can't be made working).</rant>
- I never use it (almost) and remove the padlock for almost everything.
- If I have to be careful about concurrent write access, I will look
for another, more complete solution and not only rely on the padlock.
- jfv
Le 08-03-22 à 10:07, James Cicenia a écrit :
You know this has always been a mystery to me. I rarely get
optimistic locking errrors.. about one a month, so haven't worried
too much about it. But is there a rule of thumb about which
attributes should have it turned on, and, why when you create an
attribute it is always on?
Thanks
James Cicenia
On Mar 22, 2008, at 8:51 AM, Jean-François Veillette wrote:
In addition to the good comments from Guido, I would also point
out that all your attributes are set for 'optimisting
locking' (the padlock). You probably do not want that. In fact,
considering that you might not have the time to deal with locking
problems, you probably want to remove them all just to avoid
troubles and keep things simple (even if not correct) in this
context. It you get spare time at the end, you can always get it
right.
- jfv
Le 08-03-21 à 23:46, Gustavo Pizano a écrit :
Ok so here it is my db model and my EOModel, what do you think?
is it good? the relations in EOModel? I dunno if i did it good in
EOModel based n the db design.
Regards
Gustavo<Convocationwo.eomodeld><modeloRelacional.pdf>
_______________________________________________
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
40jimijon.com
This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden