Analyze queries
How to analyze queries to identify performance problems. A step-by-step method.
Troubleshooting
Diagnostic procedures
Extract deadlock information
How to extract deadlock information.
Retrieve the error logs
How to retrieve the SQL Server error logs.
Identify excessive memory grants
How to diagnose memory grants that are too large, or too small.
Use sp_whoisactive to see the active queries
Using sp_whoisactive to see the queries currently running.
Trace execution plans
How to trace the actual execution plans of your queries.
Detect an active transaction
How to detect an active transaction in a database.