Clarify meaning of TimeRangeValueType/BeforePeriod and TimeRangeValueType/AfterPeriod (or deprecate)

sdmx-twg / sdmx-im

SDMX Information Model - UML model and functional description, definition of classes, associations and attributes

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Clarify meaning of TimeRangeValueType/BeforePeriod and TimeRangeValueType/AfterPeriod (or deprecate) #18

Open dosse opened 3 years ago

dosse commented 3 years ago

Hello, Could you please clarify the meaning of TimeRangeValueType/BeforePeriod and TimeRangeValueType/AfterPeriod especially versus TimeRangeValueType/StartPeriod and TimeRangeValueType/EndPeriod in ContentConstraints?

The IM documentations says:

BeforePeriod: The period before which the constrained selection is valid.
AfterPeriod: The period after which the constrained selection is valid.
StartPeriod: The period from which the constrained selection is valid.
EndPeriod: The period to which the constrained selection is valid.

Also see: https://github.com/sdmx-twg/sdmx-ml/blob/import21files/schemas/SDMXCommon.xsd#L903

What is justifying the existence of these different approaches? Could this be simplified (by deprecating one way of doing)?

stratosn commented 9 months ago

It looks like the TimeRange is supposed to require both a StartPeriod and EndPeriod. In any case it might make sense to keep one pair. To be discussed in the TWG.

agent96 commented 9 months ago

Unless anyone disagrees, propose to drop BeforePeriod and AfterPeriod (looks like a bug)

DrJMunozMx commented 9 months ago

Unless anyone disagrees, propose to drop BeforePeriod and AfterPeriod (looks like a bug) BeforePeriod is for reporting information that is valid until a specific date and later would be replaced for updated data

stratosn commented 9 months ago

Hi @DrJMunozMx, why wouldn't EndPeriod play the same role?

DrJMunozMx commented 9 months ago

EndPerid may play the same role. But as is now defined it is used to set the end of the period started by StartPeriod. The comment was to clarify that this is not a bug, but a question of conceptualization.

stratosn commented 9 months ago

My take on interpreting the Information Model is that it is possible to have

a time point from which something is valid,
a time point to which something is valid,
a period that something is valid

Marking this as bug was only because the above could be simply implemented using two time properties (from/to or start/end) instead of having four.

I hope that explains the rationale.