Database

Transactions as SQL Statements

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Problems occurs if we don’t implement a proper locking strategy
Dirty reads
Phantom reads
Lost updates
Unrepeatable reads
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.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is the original purpose of SQL?
To specify the syntax and semantics of SQL data definition language
To specify the syntax and semantics of SQL manipulation language
To define the data structures
All of the mentioned
Explanation:
Read committed is used to commit the default read operation.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Isolation of the transactions is ensured by
Transaction management
Application programmer
Concurrency control
Recovery management
Explanation:
ACID properties are the properties of transactions.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which of the following fixed database roles can add or remove user IDs?
db_accessadmin
db_securityadmin
db_setupadmin
db_sysadmin
Explanation:
The database can be accessed by assigning the roles.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
By default sql server has ___________ isolation level
READ COMMITTED
READ UNCOMMITTED
SERIALIZABLE
REPEATABLE READ
Explanation:
Read committed is used to commit the default read operation.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which of the following statements is/are not true for SQL profiler?
Enables you to monitor events
Check if rows are being inserted properly
Check the performance of a stored procedure
ALL of the mentioned
Explanation:
Read committed is used to commit the default read operation.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
SQL can be used to:
Create database structures only
Query database data only
Modify database data only
All of the mentioned
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.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Constraint checking can be disabled in existing _______________ and _____________ constraints so that any data you modify or add to the table is not checked against the constraint.
CHECK, FOREIGN KEY
DELETE, FOREIGN KEY
CHECK, PRIMARY KEY
PRIMARY KEY, FOREIGN KEY
Explanation:
Check and foreign constraints are used to constraint the table data.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is not a property of transactions?
Atomicity
Concurrency
Isolation
Durability
Explanation:
ACID properties are the properties of transactions.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
SNAPSHOT is used for (DBA)
Synonym
Tablespace
System server
Dynamic data replication
Explanation:
Snapshot gets the instance of the database at that time.