data-konzept

'While the difference is very important 90% of the time you won’t care and should just add the two numbers together.

I/O and Logical I/O are two pieces of information you will see all over the place. 

• SET STATISTICS IO as physical reads and logical reads

• sys.dm_exec_requests and sys.dm_exec_sessions as reads and logical_reads

• sys.dm_exec_procedure_stats and sys.dm_exec_query_stats as x_logical_readsand x_physical_reads 

Just to name a few.

There is an important difference between the two. Physical reads/IO are page reads from the disk. Logical reads/IO are pages read from memory. So why do we care? Reading from the disk is massively slower than reading from memory. '...

https://sqlstudies.com/2018/09/05/i-o-vs-logical-i-o/