How to Find and Kill Long-Running Queries in SQL Server

Anyone who works with SQL Server long enough eventually faces the same problem: a query that just keeps running. Maybe it's blocking other sessions, maybe CPU usage spikes, or maybe an application suddenly becomes slow. Long-running queries are one of the most common causes of SQL Server performance issues. In this article, we'll walk through how to: Identify long-running queries Detect blocking sessions Investigate the query details Safely terminate problematic queries Let’s get started. Why Long-Running Queries Are a Problem A query running longer than expected can cause several issues: Block other queries Consume excessive CPU or memory Lock critical database resources Slow down applications In high-traffic environments, even a single poorly optimized query can impact multiple users. That's why knowing how to quickly identify and stop problematic queries is essential. 1. Finding Long-Running Queries SQL Server provides several Dynamic Management Views (DMVs) that help monitor curren