An application uses the GetItem operation to read data from a DynamoDB table.
What strategy can be used to reduce the size of the read operations and increase read efficiency?
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A. B. C. D.Answer: D.
Option A is incorrect because filter expression can be used with Scan operations to filter the results returned by the scan operation.
It cannot be used to make GetItem operations more efficient.
Option B is incorrect because Pagination is used with Scan operations to divide the result set of the Scan operation into pages.
It cannot be used to make GetItem operations more efficient.
Option C is incorrect because Parallel Scans allows multi-threaded applications to perform Scan operations quicker.
It cannot be used to make GetItem operations more efficient.
Option D is CORRECT because Projection Expressions can be used to limit the attributes returned by the GetItem operation and thus reduce the size of the read operation.
Reference:
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.ProjectionExpressions.htmlThe correct answer is D. Use Projection Expression.
Explanation:
DynamoDB is a NoSQL database service provided by AWS that provides low-latency data access with scalability and durability. DynamoDB offers several features that can be used to optimize read operations to improve performance and reduce costs.
The GetItem operation retrieves a specific item from a DynamoDB table based on its primary key. When retrieving data using GetItem, it retrieves all attributes of the item by default. This may not be efficient if the application needs only a subset of the attributes, and if the item has a large number of attributes, it can lead to slower read operations and higher costs.
To reduce the size of the read operations and increase read efficiency, we can use Projection Expression. Projection Expression is used to retrieve only the required attributes of an item, which reduces the size of the response returned by the GetItem operation. With Projection Expression, the application can specify a list of attributes that it wants to retrieve for a specific item, rather than retrieving all attributes.
Using Projection Expression can also help reduce costs, as the application only retrieves the required attributes, and not all attributes of the item. This reduces the amount of data transferred over the network and reduces the amount of read capacity units consumed by the GetItem operation.
Option A, Use Filter Expression, is incorrect because Filter Expression is used to filter the results of a scan or query operation, not to reduce the size of read operations.
Option B, Use Pagination, is incorrect because Pagination is used to retrieve a large number of items from a DynamoDB table by dividing the results into smaller pages.
Option C, Use Parallel Scan, is incorrect because Parallel Scan is used to scan a large DynamoDB table in parallel to retrieve data quickly.