Can you explain the principle of Serializable isolation level in database transactions?

The Serializable isolation level is the strictest level of transaction isolation in databases. It guarantees that concurrently executing transactions will behave as if they were executed sequentially, one after the other.

This is achieved by preventing issues such as:

• phantom reads,
• non-repeatable reads,
• dirty reads.

In practice, this means that at the Serializable level, transactions lock the records or data ranges they work with so that other transactions cannot modify them or add new records that would affect the result.

For example, if one transaction reads a set of rows with a certain condition, another cannot add or modify rows that fall under this condition until the first transaction is completed.

This ensures maximum data integrity but may reduce performance due to locking and waiting.