Case Study … and a new tuning record!
We do a lot of performance tuning of slow SQL Server code.
In this example, I will show you how we set our personal best record!
75,336 % improvement in stored procedure performance!
- CPU from 18,922 to 1,249
- Reads from 12,850,589 to 18,532
- Duration from 30,682 to 685
It is 753x faster!
What was changed?
A SELECT with four JOINS became two SELECTs using a UNION.
That’s it. That simple!
Got any proof?
Obviously, we can just paste client code here. But here is what I can show you.
Below you will see a capture of BEFORE vs. AFTER performance tuning run. SQL proc performance BEFORE it was tuned and AFTER it was tuned.