ACID

Question 1

A

Answer 1

Atomicity (“all or nothing”)
If something goes wrong → rollback.

Question 2

C

Answer 2

Consistency (“rules stay true”)
Database goes from one valid state to another.

Question 3

I

Answer 3

Isolation (“transactions don’t interfere”)
No dirty reads, no interference.

This is where locking and serialisability live.

Question 4

D

Answer 4

Durability (“once done, stays done”)
Committed = permanent.