Op woensdag 18 januari 2006 17:10, schreef Ian McNicoll MMS: > > Either there is a documented interface to a persistence layer, or there > > isn't. It is quite possible I missed it in the documentations > > But till now, I asked it three times in three days, is there a documented > > interface to a persistence layer? Or do I have to puzzle it myself, which > > is possible, but I do not want to invent a wheel which is already there. > > As far as I am aware there is no fixed specification for a persistence > layer. From a brief chat to Thomas he indicated that a variety of > database styles were being used in live projects e.g traditional > relational databases, 'shredded' row storage such as OpenSDE, OO > databases such as db40 and cache, XML file/stream storage or newer > hybrids such as Sql Server 2005.
Thanks Ian, thanks very much, for your clear answer. When there will come no further mails which state different, I take your answer for truth. I guess I have to write it myself, or get help from people which already did. The row-storage as from OpenSDE looks as a good solution. But when this is true, and also what you state below, this means that there is still a long way to go for OpenEhr before it will be implementable. Is that true? Do I understand that well? regards Bert Verhees > > I suspect there is no correct way of doing this. It will depend on > circumstances and very rapidly changing persistence options. The whole > industry is moving to lessening the 'impedance' between structured OO > modeled code and the underlying persistence layer and as yet there does > not appear to be a single universally compelling option. > > Ian
