[Case Study] We Tuned SQL Server Performance and now TSQL runs 589 times faster(not a typo)! How did we do it?

Case study #16

Here is another recent SQL Server performance tuning report.

The stored procedure below was one of the most called on the client’s SQL Server.

Improvements achieved

  • CPU from 50 to 1
  • Reads from 2,496 to 8
  • Duration from 227 to 1

What changes made this query run faster?

  • Dropped the IX_ClientID_OrderDate;
  • Added the index IX_ClientID_OrderDate_WorkOrderNumber;

That’s it! That simple!

Why do you merge two indexes into a single one?

Because indexing is not free. The less indexes you can get away with, the faster your SQL Server run.

See more SQL Server Performance Optimization examples here.

We tune slow SQL Servers every day. For over a DECADE now. Contact us!

Mark Varnas

Mark Varnas

Hey I'm Mark, one of the guys behind Red9. I make a living performance tuning SQL Servers and making them more stable. I channel my SQL into our SQL Managed Services, SQL Consulting and our internal database products.

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