NIELIT 2017 OCT Scientific Assistant A (IT) - Section C: 5

Question

Assume transaction $A$ holds a shared lock $R.$ If transaction $B$ also requests for a shared lock on $R.$ It will

• A. result in deadlock situation
• B. immediately be granted
• C. immediately be rejected
• D. be granted as soon as it is released by $A$

Comments

https://gateoverflow.in/336886/Nielit-2017-oct-scientific-assistant-a-cs-section-b-34

Answer 1

option b will be correct because in shared mode transactions can only read data.

Answer 2

When one transaction has shared lock, other transaction can get shared lock on it. So B is correct.

Had A had exclusive lock, D would be correct on request of both shared and exclusive lock. No possibility of deadlock as there will be no circular wait when we are requesting single resource.