When you are deciding whether to materialize the data in a data model, you must take two things into consideration:

If it is acceptable to materialize the data in all of the data sets in a data model, you should materialize the entire data model, as this approach results in the best performance.

If it is acceptable to materialize the data in some of the data sets in a data model but not all, and the joins between data sets can be pushed down to the database, do not materialize the data in a .data file. Instead, use the .datadesign file and allow the database to process the joins, as this approach generally results in the best performance.

If it is acceptable to materialize the data in some of the data sets in a data model but not all, and the joins between data sets cannot be pushed down to the database, you should materialize the data in these data sets to improve performance. To materialize the data in a data set, set the data set’s isVisible property to true. If you do not want to materialize the data in a data set, set the data set’s isVisible property to false. isVisible is set to true by default.