Get prepared for your DynamoDB interview with these top 20 frequently asked questions and answers. Covering topics such as key features, scaling, data consistency, use cases, real-time analytics, data storage, data types, durability and availability, integrations with other AWS services, querying data, and secondary indexes. Master these concepts and ace your DynamoDB interview.
What is DynamoDB?
DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability.
What are the key features of DynamoDB?
Some key features of DynamoDB include: fully managed, scalable, and fast performance, support for both document and key-value data models, and support for streams and global tables.
How does DynamoDB handle scaling?
DynamoDB is designed to scale automatically to accommodate the rate of incoming requests and maintain low-latency performance. It uses adaptive capacity to automatically adjust read and write capacity settings based on actual traffic patterns.
How does DynamoDB handle data consistency?
DynamoDB provides four consistency levels for read operations: eventually consistent, strongly consistent, transactional consistent, and parallel scan consistent. You can choose the appropriate consistency level for your use case.
What are some common use cases for DynamoDB?
Some common use cases for DynamoDB include: storing user profiles, storing session data for web applications, storing metadata for serverless applications, and storing real-time analytics data.
Can DynamoDB be used for real-time analytics?
Yes, DynamoDB can be used for real-time analytics by using its Streams feature, which captures data modification events in real-time. You can use this data to trigger real-time analytics or data pipelines.
How is DynamoDB different from other NoSQL databases?
DynamoDB is different from other NoSQL databases in several ways: it is fully managed, it provides a flexible data model with support for both document and key-value data, and it has a built-in integration with other AWS services.
How is data stored in DynamoDB?
Data in DynamoDB is stored in tables, which are similar to tables in a traditional relational database. Each table has a primary key, which must be unique across all items in the table.
What are the different data types supported by DynamoDB?
DynamoDB supports the following data types: number, string, binary, boolean, and null. It also supports complex data types such as lists, maps, and sets.
How does DynamoDB handle data durability and availability?
DynamoDB stores data across multiple facilities in an AWS region, and automatically replicates data to other regions for high availability and durability. It also has built-in features such as automatic backups and point-in-time recovery to ensure data integrity.
Can DynamoDB be used with other AWS services?
Yes, DynamoDB has built-in integrations with many other AWS services, such as Amazon S3, Amazon EMR, and AWS Lambda.
How is data queried in DynamoDB?
Data in DynamoDB is queried using the primary key or a secondary index. You can use the Query API to retrieve data using the primary key, or the GSI to query data using a secondary index.
What are secondary indexes in DynamoDB?
Secondary indexes in DynamoDB allow you to query data using an alternate key, other than the primary key. This can be useful for querying data in different ways, or for creating one-to-many relationships between tables.
Can DynamoDB trigger serverless functions?
Yes, DynamoDB has built-in support for triggering serverless functions using its Streams feature. You can set up a stream to capture data modification events in real-time, and then use that data to trigger a function