Hi Karsten, Comments in text.
-Thomas Clark ----- Original Message ----- From: "Karsten Hilbert" <[email protected]> To: <openehr-technical at openehr.org> Sent: Friday, May 09, 2003 3:27 AM Subject: OODBMS, lost events; was: openEHR security; Directed to Thomas Beale > Thomas, > > >> What do you do when your object-oriented application falls > >> over ? Here, an open source application/database is even more > >> important than in plain relational DBs. > > There should be sufficient redundancy in the application to enable a > > recovery. > No, I mean when your application is dead, your vendor's dead > and you don't have the source. Isn't it much easier to extract > the data from a RDBMS or do I just not know enough about how > objects are stored in OODBMS' ? > > IOW: Is there something like the PostgreSQL shell "psql" that > lets me easily browse my data in an OODBMS no matter what > application/programming language put it there ? > Sorry. This was all too familiar a problem. Fault tolerant systems in the background causes specific responses. PostgreSql was one of the DBs I was thinking about. Regardless, the SQA background covers events that could result in the application going dead leaving one with a very short message indicating that the application is dead. Even RDBs fail, although many have had sufficient time-in-operation to have encountered the most common errors and failures. Redundancy in DB operations provides the additional resources required to recover from a significant portion of the errors and failures. Cost more though! But open-source should permit one to modify this. On a nice clear day with no problems you shouldn't have to worry about this because the SQA should have covered these issues. Should have! Database clusters (http://citeseer.nj.nec.com/504360.html), certainly not for a workstation or deskside server, but possibly for a facility or remote service. Example commercial database servers: http://www.usgenesis.com/npdbservers.html http://www.polyhedra.com/customer/Default.asp http://www.ose.com/news/pressreleases/2002/02-04-28.asp http://www.nacio.net/storage/NACIOProductBrief-DedicatedStorageArray.pdf Example medical application: http://home.mcis.washington.edu/amcis/amcissc/amcissc_11802.html http://www.biostat.wisc.edu/generaladmin/resource.html After all this the application can still die, possibly suddenly with critical impacts, which could include data loss and/or corruption. No guarentees. This is an indirect plug for external, secure Data Store Facilities which can be used to store intermediate data as well as permanent. > > Interesting example from the legal world: > > 1)Patient has never had a broken right arm > > 2)Patient enters a nursing room > > 3)Patient remains for six months > > 4)Upon discharge Patient has experienced a broken right arm > > 5)No entry in the record regarding the event and perhaps subsequent > > treatment > > > > Hence, regardless of the competence of the record-based system there will > > be situations where some things will remain the same. > Hm, I understand the content of this paragraph. I am not sure, > however, what you wanted to say with it. Did you want to say > that it can happen that events do not get recorded ? Well, > that's sure true but what wisdom does knowing that buy us ? > > Karsten Proper tracking permits the construction of a chain of events that identifies and possibly explains major events, e.g., 'broken right arm'. In the example there are several possible 'gaps' in the record. In this example everyone involved will get the opportunity to provide information outside the record. The underlying duty to update the record falls upon those with custody and/or control over the record. This is true for countless other business entities, e.g., your bank. One has the duty to properly update the record with appropriate, correct information. The information contained in the record is for the use of others beside Practitioners. > -- > GPG key ID E4071346 @ wwwkeys.pgp.net > E167 67FD A291 2BEA 73BD 4537 78B9 A9F9 E407 1346 > - > If you have any questions about using this list, > please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
