title: How to fetch query execution statistics using Oracle DB?
body: <p>I am new to database. I try to run a simple query on SQL Server 2014 and Oracle 12c. </p>
  
  <p>This is the execution plan I get using SQL Server. It contains information about I/O cost and CPU cost in seconds.</p>
  
  <p><a href="https://i.stack.imgur.com/o74Wv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o74Wv.png" alt="enter image description here"></a></p>
  
  <p>However I can't find the same information using Oracle. The CPU cost shown in the execution plan is not based on execution time.
  <a href="https://i.stack.imgur.com/ywe0h.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ywe0h.jpg" alt="enter image description here"></a></p>
  
  <p>I want to do some comparison between the two databases. How I can obtain the same information in Oracle as in SQL Server? Besides, how I can know the cache hit ratio?</p>
  
  <p>Thank you.</p>