多选题User Scott has updated the salary of one of the employees in the EMPLOYEES table and has not committed the transaction. What are the two types of locks that this scenario would lead to?()Anull lock on the row being updatedBnull lock on the table contai

题目
多选题
User Scott has updated the salary of one of the employees in the EMPLOYEES table and has not committed the transaction. What are the two types of locks that this scenario would lead to?()
A

null lock on the row being updated

B

null lock on the table containing the row

C

ROW SHARE lock for the row being updated

D

ROW EXCLUSIVE lock for the row being updated

E

shared row-exclusive lock for the row being updated

F

a shareable table lock for the table containing the row

G

exclusive table-level lock for the table containing the row

参考答案和解析
正确答案: G,C
解析: 暂无解析
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相似问题和答案

第1题:

The EMPLOYEES table contains these columns:You need to write a query that will produce these results:1. Display the salary multiplied by the commission_pct.2. Exclude employees with a zero commission_pct.3. Display a zero for employees with a null commission value.Evaluate the SQL statement:What does the statement provide?()

A. All of the desired results

B. Two of the desired results

C. One of the desired results

D. An error statement


参考答案:C

第2题:

A user needs to create a trigger that will update table T2 whenever a row is added to table T1. Assuming the user has all appropriate privileges for table T2, which privilege is required on table T1 to create the trigger?()

A.REFERENCES

B.SELECT

C.UPDATE

D.ALTER


参考答案:D

第3题:

What is true regarding InnoDB locking?()

A.InnoDB uses row and table-level locks, but row locks are not escalates

B.InnoDB locks only those rows that are updated

C.InnoDB only uses row locks, not page or table-level locks

D.InnoDB row locks may be escalated to page or table-level locks

E.InnoDB uses row-level or table-level locks depending on the number of rows affected


参考答案:B

第4题:

In which scenario do you use the Flashback Database feature?()

  • A、 when a table is dropped and you restore it from the Recycle Bin
  • B、 when a user’s schema is dropped and you recover the user’s schema
  • C、 when some incorrect data is inserted in the table and you retrieve the table to a state that was at a certain timestamp
  • D、 when a row of a table is updated frequently and committed, and you view all the versions of the row within a specific duration

正确答案:B

第5题:

The EMPLOYEES table has these columns: LAST NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement: ALTER TABLE EMPLOYEES MODIFY ( SALARY DEFAULT 5000); What is true about your ALTER statement?()

  • A、Column definitions cannot be altered to add DEFAULT values.
  • B、A change to the DEFAULT value affects only subsequent insertions to the table.
  • C、Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.
  • D、All the rows that have a NULL value for the SALARY column will be updated with the value 5000.

正确答案:B

第6题:

Examine the data in the EMPLOYEES and DEPARTMENTS tables:Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables:On the EMPLOYEES table, EMPLOYEE_ID is the primary key.MGR_ID is the ID of managers and refers to the EMPLOYEE_ID.DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table.On the DEPARTMENTS table, DEPARTMENT_ID is the primary key.Examine this DELETE statement:What happens when you execute the DELETE statement?()

A. Only the row with department ID 40 is deleted in the DEPARTMENTS table.

B. The statement fails because there are child records in the EMPLOYEES table with department ID 40.

C. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.

D. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.

E. The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.

F. The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.


参考答案:B

第7题:

A user needs to create a trigger that will update table T2 whenever a row is added to table T1. Assuming the user has all appropriate privileges for table T2, which privilege is required on table T1 to create the trigger?()

  • A、REFERENCES
  • B、SELECT
  • C、UPDATE
  • D、ALTER

正确答案:D

第8题:

The EMPLOYEES table has these columns:Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement:What is true about your ALTER statement?()

A. Column definitions cannot be altered to add DEFAULT values.

B. A change to the DEFAULT value affects only subsequent insertions to the table.

C. Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.

D. All the rows that have a NULL value for the SALARY column will be updated with the value 5000.


参考答案:B

第9题:

Which two statements complete a transaction?()

  • A、DELETE employees;
  • B、DESCRIBE employees;
  • C、ROLLBACK TO SAVEPOINT C;
  • D、GRANT SELECT ON employees TO SCOTT;
  • E、ALTER TABLE employees   SET UNUSED COLUMN sal;
  • F、Select MAX(sal)   FROM employees   WHERE department_id = 20;

正确答案:C,E

第10题:

The session of user SCOTT receives the following error after executing an UPDATE command onthe EMP table:  ERROR at line 1:  ORA-00060: deadlock detected while waiting for resource  On investigation, you find that a session opened by user JIM has a transaction that caused the deadlock.  two statements are true regarding the session of SCOTT in this scenario()

  • A、The session is terminated after receiving the error and JIM can continue with his transaction.
  • B、SCOTT should perform a COMMIT or ROLLBACK to allow JIM to continue with his transaction.
  • C、The session is rolled back after receiving the error and JIM can continue with his transaction.
  • D、SCOTT has to reexecute the last command in the transaction after he commits the transaction.

正确答案:B,D

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