Learn how to optimize performance and minimize network traffic when retrieving data from multiple Amazon DynamoDB tables by leveraging the BatchGetItem operation, efficiently fetching items from both tables in a single database operation.
Table of Contents
Question
A developer is working on a web application that uses Amazon DynamoDB as its data store. The application has two DynamoDB tables: one table that is named artists and one table that is named songs. The artists table has artistName as the partition key. The songs table has songName as the partition key and artistName as the sort key.
The table usage patterns include the retrieval of multiple songs and artists in a single database operation from the webpage. The developer needs a way to retrieve this information with minimal network traffic and optimal application performance.
Which solution will meet these requirements?
A. Perform a BatchGetltem operation that returns items from the two tables. Use the list of songName/artistName keys for the songs table and the list of artistName key for the artists table.
B. Create a local secondary index (LSI) on the songs table that uses artistName as the partition key. Perform a query operation for each artistName on the songs table that filters by the list of songName. Perform a query operation for each artistName on the artists table.
C. Perform a BatchGetitem operation on the songs table that uses the songName/artistName keys. Perform a BatchGetltem operation on the artists table that uses artistName as the key.
D. Perform a Scan operation on each table that filters by the list of songName/artistName for the songs table and the list of artistName in the artists table.
Answer
A. Perform a BatchGetltem operation that returns items from the two tables. Use the list of songName/artistName keys for the songs table and the list of artistName key for the artists table.
Explanation
The correct answer is A. Perform a BatchGetItem operation that returns items from the two tables. Use the list of songName/artistName keys for the songs table and the list of artistName key for the artists table.
In this scenario, the BatchGetItem operation is the optimal solution to retrieve multiple songs and artists from the two DynamoDB tables in a single database operation with minimal network traffic and optimal application performance.
Here’s how it works:
- The developer can perform a single BatchGetItem operation, which allows retrieving items from multiple tables in a single request.
- For the songs table, the developer should provide the list of songName/artistName key pairs, as songName is the partition key and artistName is the sort key.
- For the artists table, the developer should provide the list of artistName keys, as artistName is the partition key for this table.
- DynamoDB will then retrieve the requested items from both tables in a single network round-trip, minimizing network traffic and latency.
By utilizing the BatchGetItem operation and providing the appropriate keys for each table, the developer can efficiently retrieve the required data from both the artists and songs tables in a single database operation. This approach optimizes performance by reducing the number of network requests and leveraging DynamoDB’s efficient batch retrieval capabilities.
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