Google Cloud Professional Data Engineer — Question 264

You are using Bigtable to persist and serve stock market data for each of the major indices. To serve the trading application, you need to access only the most recent stock prices that are streaming in. How should you design your row key and tables to ensure that you can access the data with the simplest query?

Answer options

• A. Create one unique table for all of the indices, and then use the index and timestamp as the row key design.
• B. Create one unique table for all of the indices, and then use a reverse timestamp as the row key design.
• C. For each index, have a separate table and use a timestamp as the row key design.
• D. For each index, have a separate table and use a reverse timestamp as the row key design.

Correct answer: A

Explanation

The correct answer is A because using a row key that combines the index and timestamp allows for efficient querying of the most recent stock prices within a single table. Options B, C, and D do not facilitate the simplest query for the most recent data as effectively as A does, either by complicating the data structure or by separating indices into multiple tables.