Re: tree structure class

le 13/10/01 19:02, Tomas V.V.Cox à cox@idecnet.com a écrit : > Wolfram Kriesing wrote: >> >>> The url that made me understand that: >>> >>> >>> http://research.calacademy.org/taf/proceedings/ballew/index.htm >> thanks for the link, now i got it too :-) >> >> as i understand using the nested-set-model is very good for saving >> huge trees in the db, when you know the tree structure >> and when you want to work with chunks of the tree >> - how about dynamically inserting, moving and deleteing nodes? >> does everything need to be updated? >> sorry i am not too deep into this - yet > > Where this method is most powerful is retrieving data. You can easily > retrieve branchs, leaves, nodes in context ... all with only one simple > query. The insert/delete/update operations are more expensive, but not > too much. Any way the times you need to do such operations comparing > with the times you need to retrieve data is insignificant. > > I'm really interesting in develop the DB_Visitation class, I'll start > when find some time :-) It would be great to have such a class. We could then make some benchmarks against the parent-child class of Wolfram. What would be best is to use the same API if possible. I have looked at Wolfram's class and I think it is quite good. Wolfram, you should commit it ! Thanks for your work. Bertrand Mansion Mamasam