Explanation: In a concurrent execution of these transactions, it is intuitively clear that they conflict, but this is a conflict not captured by our simple model. This situation is referred to as the phantom phenomenon, because a conflict may exist on “phantom” data. 6. Which of the following fixed database roles can add or remove user IDs?
A. db_accessadmin
B. db_securityadmin
C. db_setupadmin
D. db_sysadmin
Answer:A
Explanation: In a concurrent execution of these transactions, it is intuitively clear that they conflict, but this is a conflict not captured by our simple model. This situation is referred to as the phantom phenomenon, because a conflict may exist on “phantom” data. 6. Which of the following fixed database roles can add or remove user IDs?
A. db_accessadmin B. db_securityadmin C. db_setupadmin D. db_sysadmin
Explanation: The database can be accessed by assigning the roles. 7. By default sql server has ___________ isolation level