Add a feature that splits a date period into multiple marks without adding rows to underlying data.
Because it seems many customers need a better & easier solution as documented in FAQ: Open & Close Dates
A new field type is added named date period. It requires definition of what fields constitute its start date and end date.
This could be done with two queries.
The first query is a normal query that executes with chosen row-level filters.
The second is an aggregated (cube) cross join query limited to the level needed to draw marks on the view.
With this, there is no need to reshape data and no wild increase in number of rows.
The first query is probably only loaded when users choose View data (for data source or drawn marks).
View data for drawn marks:
It should be possible to see detailed underlying data from the first query.
- Open periods (end date = null) count 1 for each underlying row in each mark where canvas date >= underlying row start date.
- A special built-in date period factor should be available in calculated fields so amounts & days can be distributed properly.