MongoDB views

Views and materialized views are essential parts of database applications, and they are supported in nearly all relational database management systems.

The main difference between the two is that a view will return the results by querying the underlying data at the time of the query, whereas a materialized view stores the view data in a distinct dataset, meaning that the result set might be outdated by the time of the query.

We can create a MongoDB view using the shell or our programming language’s driver with the following parameters:

• viewName: This field is mandatory. It refers to the name of the view.
• viewOn: This field is mandatory. It refers to the name of the collection that will be used as the data source for the view data.
• pipeline: This field is mandatory. The pipeline will execute every time we query the view. The pipeline cannot include the $out or $merge stages during any stage, including any nested pipelines.
• collation:...