Please remove me from this list. I have two email address that forward to this particular box. I am not certain which of the two is being used in regards to openEHR. Please remove both.
- mhwiii at yahoo.com - treswatson at alumni.virginia.edu Kind Regards, Tres Watson --- ns shivam <nsshivam at yahoo.co.uk> wrote: > kindly remove me from this mailing list > > Thomas Beale <thomas at deepthought.com.au> wrote: > > Tim Churches wrote: > > >On Tue, 2003-08-05 at 07:27, Thomas Beale wrote: > > > > > >>Not sure what you mean by "inefficient".. > >> > >> > > > >Well, I have changed my address several times > during my life, but not my > >sex or my name. This can be modelled by either > keeping an address > >history within my demographic record (that is, > explicitly modelling the > >time domain), or by keeping timestamped versions of > my entire > >demographic record. openEHR seems to adopt the > latter approach. > > > Actually, it doesn't, but it's not obvious I agree. > If you look at the > common RM > (http://www.openehr.org/Doc_html/Model/Reference/common_rm.htm) > you will > see that there is a class VERSION_REPOSITORY and a > class VERSION. > The former is a functional interface to the stack of > versions for one > versioned entity, which might be a PARTY, a > TRANSACTION of whatever. But > it does not say how to implement this. A > space-inefficient, but simple, > implementation would be to just have successive > complete copies. A more > efficient way would be to adopt the algorithm used > in versioning object > databases which only stores new objects in each > version, and uses > special markers for deleted objects. Normally this > would be done > backwards, so that it is always the most recent > version that is > complete, since it is the one most likely to be > retrieved all the time. > > >That > >approach is less efficient space-wise, but that > hardly matters these > >days. It is more efficient if the (medico-legal) > query is "what was my > >demographic record at date yyyy-mm-dd?" Much less > efficient if the query > >is "how many times did I change my address?". > > > for a single patient, neither of these is much work > - it's trivial, > regardless of the representation of versions > > > Very, very inefficient if > >the query is "what is the mean number of address > changes in the entire > >population?". I am thinking from an aggregate > epidemiological POV, not a > >clinical/medico-legal individual patient POV. But > then, satisfying the > >former POV is what data warehouses, populated from > EHRs, are for... > > > sure - and I agree - this is what data warehouses > are for. This kind of > querying requires forethought. If you know you are > going to be > collecting say 50 statistica, including "number of > times change > address", then you start designing software agents > to capture the data > as they go into the EHR, e.g. a simple address > change counter for your > query. Then generating the result is trivial. > > - thomas > > > - > If you have any questions about using this list, > please send a message to d.lloyd at openehr.org > > > Dr.N.S.Shivam MS,FRCS,DNB > > Head Healthcare Business development (Provider) > HCL Perot Systems > Plot No3, Sector 125, > Noida > Ph: 09811901903 > > > --------------------------------- > Want to chat instantly with your online friends??Get > the FREE Yahoo!Messenger __________________________________ Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. http://search.yahoo.com - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
