Suppose you have two data sources - in this example, two CSV files - that are identical in structure, but with different data sets.
You would like to combine these two data sources into a single data source - similar to doing a UNION of two tables.
The CSVdataC file contains these data:
The CSVDataD contains these data:
First, you will need to create these as two separate data sources in Data Discovery, using the CSV data source plugin (only CSV C data source shown here):
Also, you will need to create a Format for each data source. The purpose of the Format is to add an extra 'Type' column to designate data as coming from either source C or source D:
Having done that, you can now create a cube based on the two Formats:
Notice that both tables have been marked as 'Fact' tables.
From this cube, you can now create a table (notice, a simple table, not a cross table) where you insert all the fields as dimension values from the leftmost table (the table where the joins originate from, the C table in this example).
This is essentially the UNION result of the two data sources.
With the table done, save the dashboard. You can now use this table as a TARGIT data source for a new cube with a single fact table with the unioned data.