A database administrator is tasked with designing a MongoDB schema for a social media application that includes features for user profiles, posts, and friend connections. The application requires efficient access to a user's profile information, their posts, and their list of friends. Considering the need for high performance in both read and write operations, which schema design approach is most appropriate?
In an e-commerce application, the main entity Product includes details such as name, description, and price. Each Product can have multiple Review documents, which include ratings and customer comments. The application frequently displays products along with their reviews. How should the developer optimize the schema for read performance?
In MongoDB schema design, what is a critical implication to consider when adding another piece of data into an array field, especially in the context of document size limitations and performance?
A startup is designing a new MongoDB database to store user information and their respective device data. Each user can have multiple devices, and each device can generate daily usage statistics. The startup's application needs to frequently access a user's profile and their device's latest usage statistics. Considering scalability, efficiency, and security, which data model would best suit the startup's requirements?
In a MongoDB database, the events collection stores documents related to various events with fields like eventId, title, location, and date. The schema needs to be updated to support a new tags array field, which will store keywords related to each event. What is the most effective way to introduce this change, ensuring backward compatibility and minimal disruption to the existing application?