What types of locks are implemented in database management systems, and how are they used to ensure data integrity?

In database management systems (DBMS), the following types of locks are usually implemented to ensure data integrity:

• Row-level locks: lock individual records, allowing a high degree of concurrency.
• Table-level locks: lock the entire table, which is simpler but reduces concurrency.
• Page-level locks: lock a part of the table (a page), a compromise between row and table locks.
• Shared locks: allow multiple transactions to read data simultaneously but block writing.
• Exclusive locks: allow transactions to modify data, blocking other read and write operations.

These locks are used to implement transaction isolation and prevent issues such as dirty reads, non-repeatable reads, and phantom reads, ensuring data integrity and consistency.