SQL Query to Calculate Average Processing Time Per Machine 🚀| Leetcode 1661

SQL Query to Calculate Average Processing Time Per Machine 🚀

**Description:**
In this video, we solve a **SQL interview question** on calculating the **average processing time per machine**. We use **GROUP BY, CASE WHEN, and aggregation functions** to extract start and end timestamps, compute processing times, and find the average duration for each machine.

📌 **Topics Covered:**
✅ Extracting start and end timestamps for each `(machine_id, process_id)`
✅ Using `CASE WHEN` and `MAX()` to retrieve timestamps
✅ Calculating processing time (`end_time - start_time`)
✅ Computing the average processing time per `machine_id` using `AVG()`
✅ Optimizing SQL queries for large datasets

🔍 **Example Scenario:**
Given a table that logs machine activity with **start** and **end** timestamps, we determine how long each process runs and compute the average duration per machine. This technique is crucial in **performance monitoring, manufacturing analytics, and system efficiency analysis**.

📊 **Final Query Output Example:**
| machine_id | processing_time |
|------------|----------------|
| 0 | 0.894 |
| 1 | 0.995 |
| 2 | 1.456 |

🚀 **Watch the full video to master SQL aggregation techniques!**

🔔 **Subscribe for more SQL tutorials, data science tips, and interview questions!**
#SQL #SQLQuery #DataScience #MachineLearning #Database #SQLInterview #DataAnalytics #techtutorial