How to identify expensive SQL statements using DMV or extended events?

Hi experts,

   I monitor our SAP on SQL system recently and I find there is probably an expensive SQL statement there.

I try to use SQL statement history but the physical reads data is not very high as I expected. What's wrong?

Is there any other DMVs and extended events I should check?

Sorry for not showing DMV queried from SQL server because I am not very familiar with DMVs.

But I know those data is calculated from SQL DMV every 20 minutes.

Anyway, how do I identify SQL statement which generated heavy physical reads?

15,245 number of physical reads per second at 17:00 ~ 17:20.

Physical reads from 17:00 ~ 17:20 is just 1.1 millions which is not very high(ex: 60M)