Development with AWS Services I

Question 1

A developer is designing a new social media application to store user posts in Amazon DynamoDB. Each post includes a UserId and a PostTimestamp. The application frequently needs to retrieve all posts by a specific user, ordered chronologically by post time per user, and query posts across all users based on hashtags.

Which primary key and indexing strategy should the developer implement to efficiently support these access patterns?

A. Primary key: Partition key: PostTimestamp, sort key: UserId

Indexing: Create a Local Secondary Index (LSI) with partition key: PostTimestamp and sort key: hashtag

B. Primary Key: ...