Introduction to views
You may have noticed that when you do a search on a data source, ThoughtSpot is only able to aggregate one column by one other column. Because of this, you may come across searches you can’t do in one pass, because they are essentially nested queries. But you can create the equivalent of nested queries using a view, which is an answer that you have saved for the purpose of building other searches on top of it.
You can use a view just like any other data source. You can even link it to other sources by defining a relationship. When you save an answer as a view, and then use it as a source in a new search, it is similar to doing a nested query in SQL, only much easier to create.
To create a view, you must belong to a group that has the privilege Can administer ThoughtSpot or Can manage data. If you are not able to create views, contact your administrator and request the Can manage data privilege.
Suppose you have created a search on the sales fact table that shows the top ten Sales Reps by revenue for the first quarter. Then you want to do some further investigations on that set of data, like ranking them by how much they discounted a specific product using data from the orders fact table. Unless you save your first answer as a view, certain explorations like this won’t be possible. If you want to do this, here are the steps at a high level:
Create the first search, and save it as a view.
Create a new search that includes your view and the other sources you linked with it.
You may want to create a new worksheet that includes all these data sources.
Creating a worksheet will make it easier for people to search using your view and any related tables.
Best practices for using views
Only users with the Can administrate ThoughtSpot or the Can manage data privilege can create views and link them. Users that create views should keep in mind best practices for creating a worksheet and the boundaries around the final worksheet size.
To be able to join a view with a base table, your installation must be configured to allow this. The view cannot have more than 5 tables involved, and the number of rows in the view cannot be greater than 1000.
The order of the objects being linked (joined) matters, this is because joins are directional. The table or view with the foreign key needs to occur in the first (left) position. The table or view with the primary key should be in the second (right) position.
For the best performance, views should have 50 or fewer columns and no more than 10 million rows. Exceeding these boundaries can make your view slow. You can remedy this by materializing it.
You can use an ETL (extract, transform, load) process to circumvent these limitations.