How do you identify which query is slowing down the system?

To identify slow queries, examine:

• sys.dm_exec_query_stats – CPU, I/O, execution time
• sys.dm_exec_requests – currently running queries
• sys.dm_tran_locks – blocking analysis
• Extended Events – deep tracing
• Query Store – historical regressions

This helps pinpoint which query and which operator is causing server slowdown.