If you want to maximize data concurrency without seeing uncommitted data, which isolation level should you use?

UR (Uncommitted Read) isolation level provides maximum data concurrency while preventing access to uncommitted data. This is achieved by allowing transactions to read data that other transactions have modified but not yet committed, while still protecting against reading uncommitted changes. RS (Read Stability), CS (Cursor Stability), and RR (Repeatable Read) are more restrictive levels that reduce concurrency to prevent various types of phenomena like non-repeatable reads and phantom reads.