What is database deadlock detection and resolution strategy?

Deadlock detection identifies circular waits, and resolution aborts one transaction to break the cycle.

Deadlock detection is performed using wait-for graphs where nodes represent transactions and edges represent lock dependencies. If a cycle is detected, a deadlock exists. The database resolves it by choosing a victim transaction (based on cost, age, or rollback impact) and aborting it. Some systems use timeout-based detection instead of graph analysis.