Very interesting topic (i think) when you try to tune your SQL query and playing around with indexes. After few researches, i found this post is very useful and super easy to understand Logical and Physical read(s) – How it’s working and How to manage ? Especially the conclusion:
- All the data pages will be read from the “Physical Disk”, If the data not there in “Buffer Cache”.
- “Logical Reads” will be performed every time.
- “Physical Reads” will be performed Only when the data is not in “Buffer Cache”. NOT ALWAYS.