Top 50 DynamoDB Interview Questions and Answers 2023

DynamoDB Interview Questions: DynamoDB is a powerful NoSQL database service provided by AWS, and its popularity is on the rise. As more companies move to the cloud, the demand for professionals with DynamoDB skills is also increasing. To ace a DynamoDB technical interview, candidates need to have a strong understanding of the database’s features and capabilities which can be obtained with the help of the provided DynamoDB Technical Interview Questions. In this article, we’ll cover some of the Latest DynamoDB Interview Questions and answers, including those designed for freshers, to help you prepare for your next interview and stand out from the competition. Make use of the DynamoDB Interview Questions for Freshers presented and prepare well.

Top 50 DynamoDBInterview Questions and Answers 2023

1. What is DynamoDB?

Ans: DynamoDB is a fully-managed NoSQL database service provided by Amazon Web Services (AWS).

2. What are the benefits of using DynamoDB?

Ans: The benefits of using DynamoDB include automatic scaling, high performance, high availability, and low latency.

3. What is NoSQL?

Ans: NoSQL refers to non-relational databases that do not use SQL for querying and are designed to handle large amounts of unstructured data.

4. What are the primary components of DynamoDB?

Ans: The primary components of DynamoDB are tables, items, and attributes.

5. How does DynamoDB handle data partitioning?

Ans: DynamoDB partitions data automatically across multiple servers using partition keys and sort keys.

6. What is a partition key in DynamoDB?

Ans: A partition key is the primary key for a DynamoDB table and is used to partition data across multiple servers.

7. What is a sort key in DynamoDB?

Ans: A sort key is a secondary key for a DynamoDB table and is used to sort items within a partition.

8. What is the maximum size of a DynamoDB item?

Ans: The maximum size of a DynamoDB item is 400 KB.

9. What is the maximum size of a DynamoDB table?

Ans: The maximum size of a DynamoDB table is 10 GB.

10. How does DynamoDB handle query optimization?

Ans: DynamoDB optimizes queries by selecting the most efficient index and partition to retrieve data.

11. What is a secondary index in DynamoDB?

Ans: A secondary index is an index that allows you to query a DynamoDB table using an alternate key.

12. What is a global secondary index in DynamoDB?

Ans: A global secondary index is an index that allows you to query a DynamoDB table using an alternate key and can be created after the table is created.

13. What is a local secondary index in DynamoDB?

Ans: A local secondary index is an index that allows you to query a DynamoDB table using an alternate key and must be created when the table is created.

14. What is eventual consistency in DynamoDB?

Ans: Eventual consistency in DynamoDB means that it may take some time for all replicas of an item to be updated after a write operation.

15. What is strong consistency in DynamoDB?

Ans: Strong consistency in DynamoDB means that all replicas of an item are updated before a read operation is performed.

16. What is DynamoDB Streams?

Ans: DynamoDB Streams is a feature that allows you to capture changes to a DynamoDB table in real-time.

17. What is the difference between a DynamoDB table and a DynamoDB stream?

Ans: A DynamoDB table stores data while a DynamoDB stream captures changes to the data.

18. What is the maximum number of DynamoDB streams allowed per table?

Ans: The maximum number of DynamoDB streams allowed per table is two.

19. What is the maximum retention period for a DynamoDB stream?

Ans: The maximum retention period for a DynamoDB stream is 24 hours.

20. What is DynamoDB Accelerator (DAX)?

Ans: DynamoDB Accelerator (DAX) is a fully-managed in-memory cache for DynamoDB that provides faster performance and lower latency.

21. What is the purpose of DynamoDB Auto Scaling?

Ans: DynamoDB Auto Scaling automatically adjusts the read and write capacity of a DynamoDB table based on traffic patterns.

22. How does DynamoDB handle data encryption?

Ans: DynamoDB provides encryption at rest and in transit using AWS Key Management Service (KMS).

23. What is the difference between a strongly-typed and a weakly-typed attribute in DynamoDB?

Ans: A strongly-typed attribute in DynamoDB has a defined data type while a weakly-typed attribute does not.

24. What is the difference between a PUT and a UPDATE operation in DynamoDB?

Ans: A PUT operation in DynamoDB adds a new item or replaces an existing item while an UPDATE operation modifies an existing item.

25. What is the maximum number of items that can be retrieved in a single DynamoDB query?

Ans: The maximum number of items that can be retrieved in a single DynamoDB query is 1 MB.

26. What is the difference between a query and a scan operation in DynamoDB?

Ans: A query operation retrieves items based on a specified partition key and sort key while a scan operation retrieves all items in a table.

27. How does DynamoDB handle pagination of query results?

Ans: DynamoDB provides pagination of query results using a LastEvaluatedKey value.

28. What is the maximum size of a BatchGetItem operation in DynamoDB?

Ans: The maximum size of a BatchGetItem operation in DynamoDB is 16 MB.

29. What is the maximum number of items that can be retrieved in a single BatchGetItem operation?

Ans: The maximum number of items that can be retrieved in a single BatchGetItem operation is 100.

30. What is the difference between a BatchGetItem and a Query operation in DynamoDB?

Ans: A BatchGetItem operation retrieves multiple items from one or more tables while a Query operation retrieves items from a single table based on a partition key and sort key.

31. What is the maximum number of tables that can be created in a single AWS account?

Ans: The maximum number of tables that can be created in a single AWS account is 256.

32. What is the maximum number of secondary indexes that can be created on a single DynamoDB table?

Ans: The maximum number of secondary indexes that can be created on a single DynamoDB table is five.

33. What is the difference between a local and a global secondary index in DynamoDB?

Ans: A local secondary index is a secondary index that has the same partition key as the table while a global secondary index has a different partition key than the table.

34. What is the difference between a strong and eventual consistent read in DynamoDB?

Ans: A strong read in DynamoDB returns the most up-to-date data while an eventual consistent read may return stale data.

35. What are the different data types supported by DynamoDB?

Ans: The four scalar data types that DynamoDB supports are:

• Binary
• Boolean
• Numbers
• Strings

Data types for collections that DynamoDB supports include:

• String Set Number Set
• Differentiated Map
• Heterogeneous Binary Set
• DynamoDB accepts Null values.

36. What is the purpose of DynamoDB point-in-time recovery (PITR)?

Ans: DynamoDB point-in-time recovery (PITR) allows you to restore a table to a specific point in time.

37. What is the maximum number of tags that can be applied to a single DynamoDB table?

Ans: The maximum number of tags that can be applied to a single DynamoDB table is 50.

38. What is the difference between a conditional write and a non-conditional write in DynamoDB?

Ans: A conditional write in DynamoDB only performs the write operation if a specified condition is met while a non-conditional write always performs the write operation.

39. What is the purpose of the DynamoDB CLI?

Ans: The DynamoDB CLI is a command-line interface for DynamoDB that allows you to manage DynamoDB tables and data.

40. What is the purpose of the DynamoDB data mapper for JavaScript?

Ans: The DynamoDB data mapper for JavaScript is a library that allows you to map JavaScript objects to DynamoDB tables.

41. What is the difference between a hash key and a range key in DynamoDB?

Ans: Ahash key is a required attribute for every item in a DynamoDB table and is used to determine the partition where the item is stored. A range key is an optional attribute that is used to sort items with the same partition key.

42. What is the purpose of DynamoDB Streams?

Ans: DynamoDB Streams is a feature of DynamoDB that captures a time-ordered sequence of item-level modifications made to a table.

43. What is the difference between a stream view type of NEW_IMAGE and OLD_IMAGE?

Ans: A stream view type of NEW_IMAGE includes the new values of the modified item while a stream view type of OLD_IMAGE includes the old values of the modified item.

44. What is the difference between a stream view type of NEW_AND_OLD_IMAGES and NEW_IMAGE?

Ans: A stream view type of NEW_AND_OLD_IMAGES includes both the new and old values of the modified item while a stream view type of NEW_IMAGE only includes the new values.

45. What is the maximum size of a DynamoDB transaction operation?

Ans: The maximum size of a DynamoDB transaction operation is 4 MB.

46. What is the purpose of the DynamoDB Accelerator (DAX)?

Ans: The DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache for DynamoDB.

47. What is the difference between a reserved capacity and a provisioned capacity in DynamoDB?

Ans: A reserved capacity in DynamoDB is a commitment to pay for a certain amount of capacity for a specified period of time while a provisioned capacity is a specified amount of capacity that is allocated to a table.

48. What is the purpose of the DynamoDB backup feature?

Ans: The DynamoDB backup feature allows you to create on-demand backups and restore tables to a specified point in time.

49. What is the difference between a table backup and a table export in DynamoDB?

Ans: A table backup in DynamoDB includes all of the table’s attributes and indexes while a table export only includes the attributes that you specify.

50. What is the difference between the PutItem and BatchWriteItem operations in DynamoDB?

Ans: The PutItem operation in DynamoDB writes a single item to a table while the BatchWriteItem operation writes multiple items to one or more tables in a single request.

These Top 50 DynamoDB Interview Questions and Answers provide a comprehensive understanding of the database service. By studying and mastering these questions, candidates can confidently navigate their DynamoDB interviews and land their dream jobs. Follow our site @ freshersnow.com for more learnings.