What is the difference between row-level locks and table-level locks in Oracle?

There are two different types of locks in Oracle – row-level locks and table-level locks, and they have the following differences:

1. Scope: Row-level lock locks specific rows in a table, while table-level lock locks the entire table.
2. Granularity: row-level locks have a finer granularity, only affecting the locked row, while table-level locks have a larger granularity, affecting the entire table.
3. Concurrency: Row-level locks can simultaneously lock different rows in a table, allowing other transactions to operate on other rows concurrently, while table-level locks lock the entire table, preventing other transactions from operating on other rows in the table simultaneously.
4. Locking costs: Row-level locks consume more system resources because each locked row requires a locking data structure, whereas table-level locks only require one locking data structure.
5. Lock conflicts: row-level locks only occur on the specific rows that need to be locked and do not cause conflicts with other rows, while table-level locks can cause conflicts with the entire table, potentially leading to other transactions waiting for the lock to be released.

In general, row-level locks are suitable for controlling concurrent access to specific rows in a table in high-concurrency environments, while table-level locks are suitable for locking the entire table when operations need to be performed on the entire table.