You’re modeling IoT sensor data in Cassandra. Each sensor sends readings every minute.Which modeling strategies are recommended?

You’re storing ephemeral session data in Cassandra. Which features help manage expiry and cleanup?

A company stores customer orders in a MongoDB collection `orders`, using `customer_id` as the shard key. Most customers place only a few orders per day, but one enterprise customer places thousands of orders per minute.

You’re considering secondary indexes in Cassandra for filtering on non-key fields. What are the limitations of secondary indexes?

Which join operations are typically unsupported or discouraged in most NoSQL document stores due to architectural and performance constraints?

Which of the following MongoDB queries would fail to utilize an index efficiently?

You store product reviews in a document database. Each review includes `user_id`, `product_id`, `rating`, and `comment`. You frequently query by `product_id` and sort by `rating`.Which design choices improve query performance?

You’re building a real-time messaging app using a document database. Messages must be stored quickly and retrieved reliably. What tradeoffs are typical when choosing a document database for this use case?

You’re designing a user activity dashboard in Cassandra. Which practices align with Cassandra’s data modeling philosophy?

You’re deploying Cassandra across multiple data centers. Which consistency-related features are available?