Bert Verhees wrote: > 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. > Hi Bert,
As I promised to reply to your post on the list, here I am. :) Personally I am convinced it is possible to implement the openEHR specification even at this stage. We, at Acode, already proved it by building a pilot EHR system which meets real-life requirement. Of course, it wasn't easy since we started from scratch with the Java implementation (kernel, parser, persistence, GUI), but also the specification has been a moving target. After the version 1.0 specification is released, the situation will be quite different. Since then, there won't be any major changes on the reference model which really is the foundation of interoperable EHRs. This will hopefully encourage more open source or commercial development on openEHR in the near future. Cheers, Rong > 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 >> > >
