What are the different isolation levels in DB2 and explain each one of them?

Isolation Levels in DB2

DB2 offers different isolation levels to manage the level of concurrency and consistency in database transactions. The following are the common isolation levels in DB2:

1. Read Uncommitted: In this isolation level, transactions can read data that has been modified by other transactions but not yet committed. This can lead to dirty reads.
2. Read Committed: Transactions can only read data that has been committed. This prevents dirty reads but may still allow non-repeatable reads.
3. Repeatable Read: With this isolation level, a transaction can read the same data multiple times and is protected from other transactions committing changes to the data it has read. However, phantom reads might still occur.
4. Serializable: This is the highest isolation level in DB2, offering full data consistency. Transactions are completely isolated from each other, preventing all types of anomalies.

It is important to understand the characteristics of each isolation level and choose the appropriate one based on the requirements of the application to ensure data integrity and consistency.