[Case Study] Tuning SQL Performance and making TSQL run by 40 times faster! How did we do it?

Description:

Problem: Slowness in the biling process.
Solution: SQL code refactoring.

Time to run stored proc before tuning: 34s
Time to run stored proc after tuning: 4s

Technical Background:

Most SQL Servers bottleneck is on Disk access (or disk “reads”).

It’s not CPU or RAM – which most customers often suspect first.

And that makes much sense. Here is why.

Inefficient queries scan (or read) much data. Data read in is stored in RAM. As more data is read in, “older” data is pushed out from RAM.

If there isn’t enough RAM to keep ALL data in memory (which is often not possible), SQL Server has to read from disk – and that is the slowest operation SQL Server can do.

When the query can be tuned to read 10 rows vs. 10M – less CPU and RAM automatically are necessary.

Therefore, tuning for less disk “reads” is often the primary goal.

To the end-user, nothing is more important than Speed (or Duration of the query), in any case.

Tuning to reduce CPU/RAM resources is helpful too.

When queries are tuned to need less CPU & RAM, it means that the same server now has more capacity.

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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