To union your dataset to another, enter
union in the enter
Union datasets the Transformation textbox in the recipe panel. See Recipe Panel.
An aggregation is useful for performing exploratory calculations on your entire dataset or segments of your dataset.
You can perform aggregations and run jobs to generate the results. After you have these summary reports, you can return to the Transformer page and remove the aggregation to continue wrangling your data.
For more information on building aggregated pivot tables, see Pivot Data.