Performance

[Daulat Ram]

 Hello experts,
 
 We have the following requirements in single query or any proper solution. 
Please help on this.
How many sessions are currently opened.
 -and if opened then how many queries have executed on that session.
 -and also we have to trace how much time each query is taking.
 -and also we have to find the cost of each query.
 
 Regards,
 Daulat