I feel motivated when viewers of this blog ask me a follow-up question. Today we are going to see another demonstration which is based on my previous videos. Lots of people have asked me a very interesting question – What will happen if you use three operations COUNT(*), COUNT(1), and SUM(1) in a single statement? Will SQL Server use three scans or a single scan. Well, the answer is pretty straight forward and that is what we are going to see in today’s video of One Scan for 3 Count Sum.
Here are three blog posts you should read and watch the associated video along with it:
- SUM(1) vs COUNT(1) Performance Battle – SQL in Sixty Seconds #177
- COUNT(*) and COUNT(1): Performance Battle – SQL in Sixty Seconds #176
- COUNT(*) and Index – SQL in Sixty Seconds #175
Here is today’s blog post about One Scan for 3 Count Sum. You can also download the script of this video from the blog post here SQL Server – Single Scan for 3 Operations – COUNT(*) COUNT(1) SUM(1)
Well, that’s it for today. If you liked this video, please do not forget to subscribe to my YouTube Channel – SQL in Sixty Seconds.
Here are my few recent videos and I would like to know what is your feedback about them.
- Index Scans – Good or Bad? – SQL in Sixty Seconds #174
- Optimize for Ad Hoc Workloads – SQL in Sixty Seconds #173
- Avoid Join Hints – SQL in Sixty Seconds #172
- One Query Many Plans – SQL in Sixty Seconds #171
Published by Pinal Dave on SQLAuthority. More of my work at pinaldave.com.
Discover more from SQL Authority with Pinal Dave
Subscribe to get the latest posts sent to your email.




