dhis2-devs team mailing list archive

[Lars Helge Øverland <larshelge@xxxxxxxxx>]

Big thanks to all for illuminating the pros and cons of the current
multidimensional model. It was designed in 2006 basically to support the ICD
based dataentry, and we must admit that Bob is at least partially right when
saying that output could have been given better thought. Anyway it is not
working out too bad either it seems.

I like Bob's suggestion for simplifying the model and it would apparently
made querying easier and improve the user interface. I have a few concerns:

- Feasibility. The Category-related model is integrated into 9 out of 11
service projects in DHIS 2. Re-factoring and testing all this would take
months.
- Backwards compatibility. Lots of databases and data-entry forms exist in
the field. Conversion must be managed.
- Suitability for the data-entry module. It seems likely that the
CategoryCombo class can be "emulated" through the API.
- Does it cut tables to change from m-n to 1-n? Using join tables to
represent 1-n associations is preferred by many as it keeps the domain model
cleaner.

If people say we can live with the current model I'd say we do just that.
Anyway Bob's suggestion should be documented and looked at again later. I
think the point about "input without output is statistical m..." is valid.
At least we will need to focus more on how to make "the goodness float up".


Re the data element / indicator group set I think this is something we can
do without risk. It won't change the existing model and won't break anything
and wouldn't take too long to implement. Will start on it on Wednesday. A
minor comment here is that I believe we should keep the exclusiveness and
compulsory-ness of the group set optional (..eh) like we have it for
organisation unit group sets today.


Finally I hope people who are troubled about the lack of documentation would
use Jason's instructions and convert some of this newly discovered wisdom
into... documentation.


cheers

Lars