What is NoSQL?
Answer: NoSQL stands for "not only SQL." It's a type of database that doesn't use a traditional relational data model.
Why was NoSQL created?
Answer: NoSQL was created to handle the challenges of big data, including the need for scalability, flexibility, and high performance.
What are some examples of NoSQL databases?
Answer: MongoDB, Cassandra, Couchbase, HBase, and DynamoDB are all examples of NoSQL databases.
What are the advantages of NoSQL databases?
Answer: NoSQL databases are highly scalable, flexible, and can handle large amounts of unstructured data. They also have low latency and high availability.
What are the disadvantages of NoSQL databases?
Answer: NoSQL databases can be more difficult to query and can lack some of the features of traditional relational databases, such as transactions.
What types of data are best suited for NoSQL databases?
Answer: NoSQL databases are best suited for unstructured or semi-structured data, such as documents, images, and videos.
What are the different types of NoSQL databases?
Answer: NoSQL databases can be categorized into four types: key-value stores, document stores, column-family stores, and graph databases.
What is a key-value store?
Answer: A key-value store is a NoSQL database that stores data as a collection of key-value pairs. Examples include Redis and Riak.
What is a document store?
Answer: A document store is a NoSQL database that stores data as documents, typically in JSON or BSON format. Examples include MongoDB and Couchbase.
What is a column-family store?
Answer: A column-family store is a NoSQL database that stores data as columns instead of rows. Examples include Cassandra and HBase.
What is a graph database?
Answer: A graph database is a NoSQL database that stores data in a graph structure, where nodes represent entities and edges represent relationships between them. Examples include Neo4j and OrientDB.
What is sharding in NoSQL databases?
Answer: Sharding is the process of dividing a large dataset into smaller parts and distributing them across multiple servers.
What is replication in NoSQL databases?
Answer: Replication is the process of copying data from one server to another to ensure redundancy and high availability.
What is CAP theorem in NoSQL databases?
Answer: CAP theorem states that a distributed system can only guarantee two out of three properties: consistency, availability, and partition tolerance.
How do NoSQL databases handle ACID transactions?
Answer: NoSQL databases often use a form of eventual consistency instead of full ACID compliance, allowing for greater scalability and availability.
How does data modeling differ in NoSQL databases compared to relational databases?
Answer: Data modeling in NoSQL databases is typically more flexible and can be based on the needs of the application rather than a predefined schema.
What is document-oriented modeling?
Answer: Document-oriented modeling is a type of data modeling used in document stores, where data is stored as documents rather than in tables with fixed schemas.
What is a schemaless database?
Answer: A schemaless database is a database that doesn't enforce a fixed schema, allowing for greater flexibility and adaptability.
What is a map-reduce operation?
Answer: Map-reduce is a data processing technique used in NoSQL databases to process large amounts of data in parallel.
What is the difference between NoSQL and SQL databases?
Answer: NoSQL databases are designed to handle unstructured or semi-structured data, while SQL databases are designed for structured data.
What is denormalization in NoSQL databases?
Answer: Denormalization is the process of adding redundant data to a NoSQL database to improve query performance.
What is indexing in NoSQL databases?
Answer: Indexing is the process of creating data structures that allow for fast searching and querying of data in a NoSQL database.
What is a distributed database?
Answer: A distributed database is a database that is spread across multiple servers or nodes.
How does a distributed database differ from a traditional database?
Answer: A distributed database allows for better scalability, availability, and fault tolerance compared to a traditional database.
What is a document-oriented database?
Answer: A document-oriented database is a type of NoSQL database that stores data as documents.
What is a graph database?
Answer: A graph database is a type of NoSQL database that stores data in a graph structure.
What is a column-family database?
Answer: A column-family database is a type of NoSQL database that stores data in a column-oriented fashion.
What is the purpose of a NoSQL database?
Answer: NoSQL databases are designed to handle big data and provide better scalability, flexibility, and performance compared to traditional databases.
How does NoSQL handle data consistency?
Answer: NoSQL databases often use eventual consistency instead of strict consistency to ensure high availability and scalability.
What is the difference between horizontal and vertical scaling?
Answer: Horizontal scaling involves adding more servers to handle increased load, while vertical scaling involves adding more resources to a single server.
What is the role of a distributed cache in NoSQL databases?
Answer: A distributed cache can be used in NoSQL databases to improve query performance and reduce the load on the database.
What is ACID compliance?
Answer: ACID compliance refers to a set of properties that ensure reliable data processing and storage, including atomicity, consistency, isolation, and durability.
How does eventual consistency work in NoSQL databases?
Answer: Eventual consistency allows for updates to propagate to all nodes in a distributed system over time, rather than enforcing strict consistency at all times.
What is the difference between a document and a row in a NoSQL database?
Answer: A document is a self-contained unit of data, typically stored as a JSON or BSON object, while a row is a unit of data in a table with a fixed schema.
What is the role of sharding in NoSQL databases?
Answer: Sharding allows for better scalability by distributing data across multiple servers.
What is the role of replication in NoSQL databases?
Answer: Replication ensures high availability and fault tolerance by copying data to multiple servers.
What is the difference between a primary key and a partition key in NoSQL databases?
Answer: A primary key uniquely identifies a record in a database, while a partition key is used to partition data across multiple servers.
What is a NoSQL data warehouse?
Answer: A NoSQL data warehouse is a type of database used for storing and analyzing large amounts of data.
What is the role of caching in NoSQL databases?
Answer: Caching can be used to improve query performance and reduce the load on the database by storing frequently accessed data in memory.
What is the difference between a distributed database and a federated database?
Answer: A distributed database is a single database spread across multiple servers, while a federated database is a collection of databases that appear as a single database.
What is the role of indexes in NoSQL databases?
Answer: Indexes allow for fast searching and querying of data in a NoSQL database.