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3. Architecture & Database
14. What are the differences between microservices and monolithic architectures?
A monolithic architecture is a single, unified unit where all components are interconnected. Microservices architecture breaks the application into smaller, independent services that communicate with each other, usually via APIs.
15. What is the difference between SQL and NoSQL databases?
SQL databases are relational, table-based, and have a predefined schema (e.g., MySQL, PostgreSQL). NoSQL databases are non-relational, document, key-value, or graph-based, and have dynamic schemas for unstructured data (e.g., MongoDB, Redis).
16. Can we store images or PDFs in a database?
Yes, as BLOB (Binary Large Object) data, but it is generally recommended to store the files in a file system or cloud storage (like AWS S3) and store only the reference path/URL in the database.
17. Explain some basic SQL queries you can write?
SELECT * FROM table_name; (Retrieve data), INSERT INTO table_name VALUES (...); (Add data), UPDATE table_name SET column=value; (Modify data), DELETE FROM table_name WHERE condition; (Remove data).