[Opensim-dev] SceneObjectGroup vs SceneObjectPart

[Sean Dague]

On Tue, Jan 22, 2008 at 05:00:46PM +0100, Stefan Andersson wrote:
> Ok guys,
>  
> since we haven't started the 0.6 discussion, I'd like to kick off with a couple of observations;
>  
> * We need to revise the SceneObjectGroup/SceneObjectPart bit as it
> stands for several reasons: 1) It doesn't hold for attachments  2) It
> doesn't hold as a object model (we still have that root mess)  3) It's
> a hell of a lot of duplication, as several fields aren't used on child
> objects (like permissions and objectflags) and it's real bad db
> normalization.

It would be good to see a proposal on how to change those objects into
something better.  None of us are in love with them, but better
approaches haven't popped up yet.

> * Related, we need to revise the xml serialization scheme and the db
> * schemes. The xml scheme should be user-friendly to the point where
> * you should be confident to create and edit objects in notepad,
> * basically. This is not the case at the moment. Massive duplication,
> * weird bit values and non-intuitive value ranges are king at the
> * moment.

Given the amount of data in a prim, editing in notepad always is going
to be a bad idea. :)  I think we've got something like 40 fields that
have to be sensible for the prim to work.

> We need to kickstart these issues, I'm not entirely sure how. I do
> know that these kinds of radical changes are seriously hampered by the
> need for backwards compatibility; we now see ourselves painting
> ourselves into the very same kinds of corners that made other
> companies choose really weird solutions - the question is if we are
> going to go down the same route?

My theory on data migration is to build something akin to the
db:migration model in rails, which will let us version forward in an
incremental way.  I think past experience has proven that we aren't
going to have a fixed db structure for a while, so flag days and full
burn downs aren't the best approach.

     -Sean

-- 
__________________________________________________________________

Sean Dague                                       Mid-Hudson Valley
sean at dague dot net                            Linux Users Group
http://dague.net                                 http://mhvlug.org

There is no silver bullet.  Plus, werewolves make better neighbors
than zombies, and they tend to keep the vampire population down.
__________________________________________________________________
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://opensimulator.org/pipermail/opensim-dev/attachments/20080122/fdfc0836/attachment-0001.pgp>