One reason for the question was that it wasn't clear whether the atxxxx uniquely identifies a concept within the ADL. I think it still does, but it can have different context depending on where it occurs.
Implementing a hierarchy of information (information model) using entity relationships (data model) is common place. The argument of Object databases versus Relational databases is an old one that I expect most people have already chosen their camp based upon their personal career experiences. I will agree with you that MySQL is not well suited to terabyte databases with 1000's of concurrent users, with many people attempting to update the same patient record :-) My own hospitals largest table is growing at a rate of 500,000 rows per day, MySQL would choke with the number of queries and updates hitting it regardless of hardware IMHO. Greg http://www.patientos.org On 11/5/07, Tim Cook <timothywayne.cook at gmail.com> wrote: > On Mon, 2007-11-05 at 06:18 -0500, Greg Caulton wrote: > > > Of course that would break if a new data element was added in a > > position (fabricated) > > data[at0001]/events[at0099]/data[at00100]/items[at0004]/value but the > > simplicity is tempting. > > This is of course why you should (IMHO) change your focus (it takes an > "Ah Ha moment") from "data model" to "information models". > > Using an object database (ZODB, POET, Gemstone, Versant, Objectivity/DB, > etc.) in your chosen implementation language is usually transparent at > that point. > > If your heart can't handle that (OODB) approach for some reason and you > insist on PostgreSQL or Oracle (please do NOT use MySQL for healthcare > information) you should still look at using the custom data type > capabilities of them and follow the information model as defined in the > specifications. Again, you end up with an information model approach > and you do not adhere to (necessarily) to a relational model but you > still maintain data integrity and the relationships defined in the > information model UML. > > DISCLAIMER: I understand that Ocean Informatics uses MS-SQL but I do not > know what their "data model"/"information model" looks like at the > persistence level. The really cool thing about truly supporting the > openEHR Information Models is that it doesn't matter as long as you can > support and EHR Extract in context of the information requested. > > My 1 cent (the USD is in trouble). > > Cheers, > Tim > > > -- > Timothy Cook, MSc > Health Informatics Research & Development Services > http://timothywayne.cook.googlepages.com/home > > LinkedIn Profile:http://www.linkedin.com/in/timothywaynecook > > > _______________________________________________ > openEHR-technical mailing list > openEHR-technical at openehr.org > http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-technical >
