What types of locks are used in database management systems to ensure data integrity?

In a DBMS, various types of locks are used to ensure data integrity:

• Row-level locks — lock individual records, allowing other transactions to work with the remaining data.
• Table-level locks — lock the entire table, preventing access by other transactions.
• Page-level locks — lock specific data pages within a table.
• Shared locks — allow multiple transactions to read data but prevent writing.
• Exclusive locks — prevent other transactions from reading or writing.

For example, when performing a record update, the DBMS may set an exclusive lock on that row to prevent other transactions from modifying it simultaneously, which prevents data loss and ensures consistency.