Interview Q&A / SQL & DBMS
SQL & DBMS interview questions
Joins, keys, normalisation, indexes and transactions for placement and backend interviews.
Prefer rapid revision? Practise SQL & DBMS short interview answers →
- What are the four transaction isolation levels in SQL?
From weakest to strongest they are READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ and SERIALIZABLE. Higher levels prevent more anomalies such as dirty reads, non-repeatable reads and phantoms, at the cost of concurrency.
IntermediateQuick answer1 min read