What is it?
ACID is a acronym for four words: Atomicity, Consistency, Isolation, Durability. This are the values that most normal SQL DB implement, such as PostgreSQL, MySQL, and any old traditional SQL DB.
Those values are important, because together they create a strong foundation to make SQL one of the best:
- Atomicity: Ensures that all operations occur in a all or nothing state. No half committed query or data changed.
- Consistency: Restraints applied into every single query, mutation, this ensure overall data consistency across the DB.
- Isolation: The guarantee that changes and queries in the DB doesn’t suffer from race conditions that would allow invalid data to be committed.
- Durability: The fact that on commit, every DB operation is written to a WAL, which prevents queries to not commit, even on DB crashes.