text: USE AdventureWorks2017;
  GO
  
  -- Reads all 31465 rows
  SELECT  soh.SalesOrderID
  FROM    Sales.SalesOrderHeader AS soh;
  
  -- Reads only 5 rows
  SELECT  TOP (5) soh.SalesOrderID
  FROM    Sales.SalesOrderHeader AS soh;
  
  -- Reads 1862 rows to returns 5 rows
  SELECT  TOP (5) soh.SalesOrderID
  FROM    Sales.SalesOrderHeader AS soh
  WHERE   soh.DueDate = '20120210'
  GO
  