An online gaming company is planning to launch a new game with Amazon DynamoDB as its data store. The database should be designated to support the following use cases: - Update scores in real time whe

Question

Options

• ACreate a global secondary index with game_id as the partition key
• BCreate a global secondary index with user_id as the partition key
• CCreate a composite primary key with game_id as the partition key and user_id as the sort key
• DCreate a composite primary key with user_id as the partition key and game_id as the sort key

• A
  5% (2)
• B
  15% (6)
• C
  3% (1)
• D
  78% (31)

Explanation

Explanation

Option D is correct because using user_id as the partition key and game_id as the sort key directly supports both use cases: real-time score updates can target a specific player (via user_id), and retrieving a player's score for a specific game session is efficiently handled by querying the composite key (user_id + game_id together) without any additional index overhead.

Why the distractors are wrong:

• A & B are wrong because Global Secondary Indexes (GSIs) are supplementary access patterns - they add cost and complexity when a well-designed primary key already satisfies the query requirements natively.
• C is wrong because making game_id the partition key would cluster all players of the same game together, making it inefficient to quickly retrieve or update a specific player's score - the dominant use case here.

Memory Tip: Ask yourself "Who is the primary actor?" - in player-centric applications, the player (user_id) should be the partition key, because most queries start with "give me data for THIS player." The sort key (game_id) then narrows down which game session, perfectly matching both requirements.

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