Which of the following describes the objects of a DB2 database and their relationships?（）

单项选择题Which of the following DB2 objects are publicly referenced names that require no special authority or privilege to use them?（）

A.View
B.Alias
C.Table
D.Package

单项选择题Given the following statements: CREATE TABLE tab1 (col1 INT); CREATE TABLE tab2 (col1 INT); CREATE TRIGGER trig1 AFTER UPDATE ON tab1 REFERENCING NEW AS new1 FOR EACH ROW MODE DB2SQL INSERT INTO tab2 VALUES(new1.col1); INSERT INTO tab1 VALUES(2),(3); What is the result of the following query? SELECT count(*) FROM tab2;（）

A.3
B.2
C.1
D.0

单项选择题A number of applications issue the following SQL statement:SELECT d.deptno, e.empno, e.salary FROM department d INNER JOIN employee e ON d.deptno = e.deptnoA database administrator wishes to store this query within the database. Which of the following database objects can be used to accomplish this?（）

A.Alias
B.View
C.Schema
D.Trigger

单项选择题The following statements: CREATE TABLE t1 (col1 INT NOT NULL, PRIMARY KEY(col1)); CREATE TABLE t2 (col1 INT NOT NULL, col2 CHAR(1) NOT NULL, PRIMARY KEY (col1, col2), FOREIGN KEY (col1) REFERENCES t1 (col1) ON DELETE CASCADE ON UPDATE RESTRICT); CREATE TABLE t3 (col1 INT NOT NULL, col2 INT NOT NULL, PRIMARY KEY (col1, col2),FOREIGN KEY (col1) REFERENCES t1 (col1) ON DELETE NO ACTION ON UPDATE RESTRICT);INSERT INTO t1 VALUES (1), (2); INSERT INTO t2 VALUES (1, a), (1, b), (2,c); INSERT INTO t3 VALUES (1, 100), (2, 200), (2,300); How many rows will be deleted by the following DELETE statement? DELETE FROM t1 WHERE col1= 1;（）

A.4
B.3
C.1
D.0

单项选择题Within the application MY_APP the following PREVIOUS VALUE expression references the sequence MY_SEQ: PREVIOUS VALUE FOR my_seq After which of the following events will the most recently generated value of MY_SEQ persist so that it can be returned to the active MY_APP application?（）

A.After a ROLLBACK is issued
B.After the sequence is altered
C.After the sequence is dropped
D.After the current session ends