Extended Events

Extended Events (often abbreviated as XEvents) is a lightweight performance monitoring system built into SQL Server. It
provides a powerful, scalable framework to collect diagnostic and performance data with minimal overhead. As the successor to SQL Trace and SQL Server Profiler, Extended Events offer fine-grained control over what data is captured and how it’s analyzed.

At its core, an Extended Events session consists of:

• Events: specific occurrences in SQL Server (e.g., query execution, deadlocks, waits).
• Predicates: filters to determine which events to capture.
• Actions: additional contextual information to include with events (e.g., session ID, SQL text).
• Targets: destinations for captured data (e.g., memory buffer, event file).

Extended Events are integrated with Dynamic Management Views (DMVs), allowing programmatic access and analysis via T-SQL. You can also view and manage sessions through SQL Server Management Studio (SSMS), which provides a UI for creating sessions and analyzing results.

Key benefits:

• Lower performance overhead than SQL Profiler or server-side traces.
• Scalability for high-throughput environments.
• Customizability—you can define your own session templates, filter by user, duration, CPU usage, or any attribute.
• System-wide visibility — Extended Events go beyond SQL queries to include OS interactions, memory pressure, and hardware
  performance counters.

Example use cases:

• Identifying long-running queries
• Diagnosing deadlocks
• Tracking login failures
• Monitoring wait statistics

Because it’s extensible and event-driven, Extended Events is favored by advanced DBAs and Microsoft support engineers alike. If you need to troubleshoot performance without impacting production workloads, Extended Events is a best-in-class diagnostic tool.