dhis2-devs team mailing list archive

[Ola Hodne Titlestad <olati@xxxxxxxxxx>]

On 7 December 2010 09:48, <johansa@xxxxxxxxxx> wrote:

> Dear Thuy
>
> > Dear Johan,
> > Thank you for your suggestions. Please scroll down to see my mail
>
> > on this. That's why I consult you to know what will happen in the future
> > when data base become huge if we use category options like this for data
> > elements? Is it affecting to retrieving information later?
>
> I don't know too much about this, but think Knut sums it up. The only
> obvious place that I see where this can cause problems is in pivot tables.
> Since pivot tables usually are distributed to also those not too familiar
> with the database setup, this can be confusing.
>
> >> Second, regarding the parent/child/grandchild totals, I think it should
> >> be
> >> possible to set aggregation start levels, meaning you could use the same
> >> data element definitions for all levels without running into
> >> double/triple
> >> counting. But others would need to fill in about this.
> >>
> >
> > I don't understand much about this. Please give more suggestions.
>
> Here also I'm not 100% sure, but if you go to edit data element, you will
> find the Aggregation Level check box, which if checked will produce a
> drop-down list of all the levels you can aggregate data from. From the
> manual:
>
> "Aggregation levels: The Aggregation Levels option allows the data element
> to be aggregated at one or more
> levels. When the user clicks on the Aggregation levels option, a drop down
> menu appears which displays available
> aggregation levels. The desired aggregation level is then selected by
> clicking the ‘Add Selected’ button. By default,
> the aggregation will start at the lowest assigned organisation unit."
>
> I'm not sure if this adequately explains the funcionality. Others would
> need to help here, but I *think* this is working by setting the levels
> that will use "it's own" data rather than aggregate from below. Default
> only the lowest level is selected, and all higher levels will use data
> from that level. For example, if you have three levels; Facility,
> District, National, the last two levels will by default aggregate the data
> from Facility. If you select District as aggregation level, queries on
> Facility will use Facility data, District will use District Data, and
> National will aggregate District data. So in the Sri Lanka case, you can
> have one data element that you can use for all levels, just set it to have
> all aggregation levels. But not 100% sure about this, so good if someone
> can confirm. Also not sure aggregation level is the best name, I vaguely
> remember some discussion about this.
>
>
This explanation is correct. It is a lot more in the manual than what Johan
pasted, see 10.2.1.5 (Aggregation Levels).

Ola
--------


> Regards,
> Johan
>
>