Free MongoDB Associate-Data-Modeler Exam Questions

In a MongoDB database for an online bookstore, you're designing a data model to handle books, authors, and reviews efficiently, considering a complex scenario involving relationships and potential data skew due to varying numbers of reviews per book. Given the requirements:

Each book can have multiple authors.

Each author can write multiple books.

Books can have a large number of reviews, but most have a few or none, creating potential data skew.

The application frequently queries books with their authors and a sample of reviews to avoid performance issues due to data skew.

How should you model the relationships among books, authors, and reviews to optimize for query performance and data management?

A data modeler is tasked with enhancing query efficiency for the salesRecords collection. Considering the queries:

db.salesRecords.find({"productId": 15}).sort({"saleDate": -1, "quantity": 1})

and

db.salesRecords.find({"saleDate": {"$gte": ISODate("2023-06-01")}}).sort({"productId": 1, "quantity": -1})

which indexing strategy would be most effective in improving response times for both queries?

In designing a data model for a new online bookstore application, you are tasked with structuring the relationship between Books and Authors. Each book can have one or more authors, and each author can write multiple books. Considering the requirement for fast reads and updates of both books and their associated authors, which of the following data modeling patterns would be most optimal?

In a blogging application, the main entity Article contains text, a title, and metadata. Each article can have multiple comments made by users. The application frequently retrieves an article along with all its comments for display. How should the developer optimize the schema for read performance?

In designing a database schema for a MongoDB application that handles user-generated content, such as posts and comments, a data modeler is considering the most efficient way to store comments related to each post to optimize read operations, as the application experiences significantly more reads than writes. The application requires frequent retrieval of posts along with their associated comments. What pattern should the data modeler use to store comments in relation to posts, and why?