On 27/04/2007, at 11:53 PM, Mike Kienenberger wrote:
> Not sure how Entity Modeler does it, but Cayenne Modeler has a
> checkbox that you can use to apply the locking/non-locking state to
> every attribute of every entity.
Entity Modeler (and EOModeler for that matter) has the option per
attribute.
> As for full optimistic locking (which is what you're doing if you lock
> by every attribute), the advantage is that you only have an optimistic
> locking failure if your current data state doesn't match the actual
> data state in the database.
There are just some attributes where such comparisons are
unwarranted. e.g., BLOBs, and so forth.
> Ie, you read in your data, other processes make net efffect noop
> changes to the data, and then you write out your data without any
> locking exception.
>
> This also means that you don't have to maintain a version attribute or
> a last modified attribute for every table since the locking is based
> on actual data values and not an arbitrary locking column in the
> table.
Sure. But the modified attribute also provides information for us.
When present it seems to me to be the only necessity for locking (so
long as you always update it prior to commit).
Anyway this bug report was not about the reasons for choosing a
certain approach (as that can depend on the particular application)
but that there is a need to minimise the tool getting in the way.
as an aside, and the reason why this bug report was lodged, was
especially because I found that the more entities I added to the
model the slower Entity Modeler was, with all the notifications and
whatever it was doing in the background (I suppose verifying the
model with every action). Thus, little things like this became
increasingly irritating as it was just another thing that slowed the
process down for modelling the entities.
e.g., Clicking on the "Add new attribute" button five times in a row
would take longer than 5 seconds to populate. Beach-ball city after a
while... and clicking each of the attributes locking to untick the
ones I wanted unticked, took too long also. Too much mouse clicking.
All in all, I'm all for making stuff like this a preference.
Over and out :-)
with regards,
--Lachlan Deck
This archive was generated by hypermail 2.0.0 : Fri Apr 27 2007 - 10:47:30 EDT