What is isolation level in SQL?

Can you explain the different isolation

levels (e.g., READ UNCOMMITTED, READ COMMITTED, REPEATABLE

READ, SERIALIZABLE)?

The isolation level in SQL defines how transactions interact with each other in terms of

visibility of data. The isolation level affects the balance between data consistency and

transaction concurrency.

• READ UNCOMMITTED: Allows dirty reads. One transaction can see uncommitted

changes made by another transaction. This is the lowest level of isolation.

• READ COMMITTED: Prevents dirty reads, but allows non-repeatable reads (data

can change during the transaction).

• REPEATABLE READ: Prevents dirty reads and non-repeatable reads, but phantom

reads (new rows can appear in a query) are still possible.

• SERIALIZABLE: The highest isolation level. Prevents dirty reads, non-repeatable

reads, and phantom reads by making transactions execute sequentially.