单项选择题
Which object may be used during query optimization to improve the performance for a subset of SELECT queries?（）
A.MQT
B.Trigger
C.Read Only Cursor
D.Stored Procedure
相关考题
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单项选择题
To which of the following resources can a lock be applied?（）
A.Row
B.Alias
C.Bitmap
D.Column -
单项选择题
Application A holds an Update lock on a single row and application B is trying to read that row. If both applications are using isolation level UR, which of the following will occur?（）
A.Application B will read the row.
B.Applications A and B will cause a deadlock situation.
C.Application B will wait until application A releases the Update lock.
D.Application A will be terminated so that application B can read the row. -
单项选择题
Application A is designed to execute the following SQL statements within a single Unit of Work (UOW). UPDATE employee SET salary = salary * 1.1 WHERE empno=000010 UPDATE department SET deptname = NEW dept WHERE deptno=A00Application B is designed to execute the following SQL statements within a single Unit of Work (UOW). UPDATE department SET deptname = OLD DEPT WHERE deptno=A00 UPDATE employee SET salary = salary * 0.5 WHERE empno=000010 Application A and application B execute their first SQL statement at the same time. When application A and application B try to execute their second SQL statement, a deadlock occurs. What will happen?（）
A.The database manager will rollback the transaction in both applications.
B.The database manager will rollback the transaction in one of the two applications.
C.Application B will successfully update the EMPLOYEE and DEPARTMENT tables; Application A will be placed in a lock wait state.
D.Application A will successfully update the EMPLOYEE and DEPARTMENT tables; Application B will terminate when the lock timeout value is reached.
