#Database

52 questions

What is SQL and what is it used for?SQL#databaseJunior
How does NULL behave in SQL?SQL#databaseJunior
What are primary keys and foreign keys?SQL#databaseMiddle
What database constraints are there?SQL#databaseMiddle
What is database normalization?SQL#databaseMiddle
What are transactions and ACID properties?SQL#databaseMiddle
What are views and materialized views?SQL#databaseMiddle
What are transaction isolation levels?SQL#databaseSenior
What causes deadlocks and how do you prevent them?SQL#databaseSenior
What are stored procedures and when should you use them?SQL#databaseSenior
What are DDL, DML, DCL and TCL?SQL#databaseSenior
What are common SQL data types and how do you choose them?SQL#databaseMiddle
What is PostgreSQL and why choose it?PostgreSQL#databaseJunior
What data types does PostgreSQL offer beyond standard SQL?PostgreSQL#databaseJunior
What is psql and what are its essential commands?PostgreSQL#databaseJunior
How do auto-incrementing IDs work (SERIAL, sequences, IDENTITY)?PostgreSQL#databaseJunior
What are schemas in PostgreSQL?PostgreSQL#databaseJunior
How do array columns work in PostgreSQL?PostgreSQL#databaseJunior
What are generated columns?PostgreSQL#databaseJunior
How does JSONB work and when should you use it?PostgreSQL#databaseMiddle
How does full-text search work in PostgreSQL?PostgreSQL#databaseMiddle
What is MVCC in PostgreSQL?PostgreSQL#databaseMiddle
What are PostgreSQL extensions?PostgreSQL#databaseMiddle
What are LISTEN and NOTIFY?PostgreSQL#databaseMiddle
What constraints does PostgreSQL support?PostgreSQL#databaseMiddle
How does locking work in PostgreSQL?PostgreSQL#databaseSenior
What is MongoDB and how does it differ from SQL databases?MongoDB#databaseJunior
What are documents and collections in MongoDB?MongoDB#databaseJunior
What is BSON and what data types does MongoDB support?MongoDB#databaseJunior
What is the MongoDB shell (mongosh) and its essential commands?MongoDB#databaseJunior
How does text search work in MongoDB?MongoDB#databaseMiddle
How do transactions work in MongoDB?MongoDB#databaseMiddle
What is Mongoose and why use an ODM?MongoDB#databaseMiddle
How does schema validation work in MongoDB?MongoDB#databaseMiddle
What are change streams?MongoDB#databaseSenior
How do write concern and read concern affect consistency?MongoDB#databaseSenior
What is Redis and what is it used for?Redis#databaseJunior
What data types does Redis support?Redis#databaseJunior
How do strings and keys work in Redis?Redis#databaseJunior
How does key expiration (TTL) work in Redis?Redis#databaseJunior
How do Redis lists work and how are they used for queues?Redis#databaseJunior
How do Redis hashes and sets work?Redis#databaseJunior
What are sorted sets and how are they used?Redis#databaseJunior
What is redis-cli and its essential commands?Redis#databaseJunior
How does Redis differ from a traditional database?Redis#databaseJunior
How does Redis persistence work (RDB vs AOF)?Redis#databaseMiddle
How do Redis transactions work?Redis#databaseMiddle
Why are Redis operations atomic and why does it matter?Redis#databaseMiddle
How does Lua scripting work in Redis?Redis#databaseSenior
What advanced Redis data structures and modules exist?Redis#databaseSenior
What is Amazon DynamoDB?Cloud & AWS#databaseMiddle
How do you optimize a slow database query?Site Reliability & Operations#databaseMiddle