dhis2-devs team mailing list archive

[Lars Helge Øverland <larshelge@xxxxxxxxx>]

Hi,

I see the need for introducing an association between DataElement and
PeriodType in the DHIS 2 data model. Currently you can look up the
PeriodType of the DataSet of which the DataElement is a member, but this is
not enforced as a DataElement can be a member of many DataSets. The need is
based on a few new requirements:

- Sierra Leone: Regression analysis where missing values are left out of the
aggregated indicator value. In order to define a missing value for a data
element, we need to know the PeriodType of the Periods to look for.

- South Africa: Gap analysis. In order to define a gap, we need to know the
PeriodType of the Periods to look for.

- South Africa: Alignment of the DHIS 2 and DHIS 1.4 data model which is
necessary for migration and data dictionary use.

- India: Aggregated data export. We must know the PeriodType of the Periods
that should be used to aggregate data for each DataElement in order to avoid
duplication of data on higher levels.

- General: Improved performance in datamart as you can reduce the number of
crosstabulated Periods.


The downside of this is that all current DHIS 2 databases must be updated by
assigning a PeriodType to each DataElement. Also this will affect places
where data is captured with different frequencies for the same DataElement
(this might be considered a bad practise anyway).

As an intermediate step we could disable this functionality for databases
where DataElements registered for DataSets with different PeriodTypes exist.


I would prefer introducing this association. Please comment on this.


regards, Lars