多选题Given:
2. public class Kant extends Philosopher {
3. // insert code here
5. public static void main(String[] args) {
6. new Kant("Homer");
7. new Kant();
8. }
9. }
10. class Philosopher {
11. Philosopher(String s) {System.out.print(s + " "); }
12. }
Which set(s) of code, inserted independently at line 3, produce the output "Homer Bart"? (Choose all that apply.)
多选题用户以wuda身份登录，之后发出如下的查询语句，请问这一查询语句将完成什么任务? SELECT * CFROM USER_CONS_COLUMNS; A．计算在这一模式中UNIQUE约束的个数 B．显示该用户可以访问的表上的约束名 C．显示该用户所拥有的表上的相关约束的列 D．决定在用户jinlian模式中DEPARTMENT表的DEPT_ID列上约束的类型
多选题为什么要查询数据字典dba_free_space? A．显示一个表的属主 B．确定任何一个段被创建的时间 C．显示在一个表空间中的空闲块的个数 D．确定当前分配给一个表的区段个数
多选题在下面的列表中，选择4个可用于启用ARCHIVELOG模式的最佳命令，并且按序排列：
1．STARTUP MOUNT
2．SHUTDOWN ABORT
3．ALTER DATABASE ARCHIVELOG
4．STARTUP FORCE
5．ALTER DATABASE ENABLE ARCHIVELOG
6．ALTER SYSTEM SWITCH LOGFILE
7．SHUTDOWN NORMAL
8．ALTER DATABASE OPEN
9．SHUTDOWN IMMEDIATE
多选题Given:
2. class Feline { }
3. public class BarnCat2 extends Feline {
4. public static void main (String[] args) {
5. Feline ff=new Feline();
6. BarnCat2 b=new BarnCat2 ();
7. // insert code here
8. }
9. }
Which, inserted independently at line 7, compile? (Choose all that apply.)
多选题在星期一使用主键索引创建了VAC_SCHED表；创建表后紧接的SCN是5680123。于星期三删除了索引。在星期四无意间删除了数据库中的大部分行。在星期五执行以下命令：
SQL＞FLASHBACK TABLE VAC_SCHED TO SCN 5680123;
已经将担保撤消保留期限设置为一个星期。运行此命令会有什么结果?
多选题Given:
3. public class Limits {
4. private int x = 2;
5. protected int y = 3;
6. private static int m1 = 4;
7. protected static int m2 = 5;
8. public static void main(String[] args) {
9. int x = 6; int y = 7;
10. int m1 = 8; int m2 = 9;
11. new Limits().new Secret().go();
12. }
13. class Secret {
14. void go() { System.out.println(x + " " + y + " " + m1 + " " + m2);}
15. } }
What is the result?
多选题创建副本数据库时，给下面的步骤指定正确的顺序：
1．以NOMOUNT模式启动辅助实例
2．在必要时分配辅助通道
3．运行RMAN DUPLICATE命令
4．为辅助实例创建口令文件
5．确保辅助实例的网络连接
6．打开辅助实例
7．在MOUNT或OPEN模式下启动源数据库
8．为辅助实例创建一个初始化参数文件
9．创建备份，或者将现有的备份和归档日志文件复制到辅助实例可以访问的公共位置
多选题Given:
3. class A { }
4. class B extends A { }
5. class C extends B { }
6. public class Carpet＜V extends B＞ {
7. public ＜X extends V＞ Carpet＜? extends V＞ method(Carpet＜? super X＞ e) {
8. // insert code here
9. } }
Which, inserted independently at line 8, will compile? (Choose all that apply.)
多选题Given that IllegalArgumentException extends RuntimeException, and given:
11. static String s = "";
12. public static void main(String[] args) {
13. try {doStuff(); }
14. catch (Exception ex) {s += "c1 "; }
15. System.out.println(s);
16. }
17. static void doStuff() throws RuntimeException {
18. try {
19. s += "t1 ";
20. throw new IllegalArgumentException();
21. }
22. catch (IllegalArgumentException ie) {s += "c2 ";
23. throw new IllegalArgumentException();
24. }
What is the result?
多选题学生(STUDENT)表包括了如下的列定义：
ID NUMBER(9) PK
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
SUBJECT_ID NUMBER(9)
比较以下的两个SQL语句，其结果将有哪些不同?
(1)SELECT DISTINCT subject_id, last_name, first_name
FROM student
ORDER BY 1;
(2)SELECT id, last_name, first_name, subject_id
FROM student
ORDER BY subject_id;
多选题Given:
2. public class Humping {
3. public static void main(String[] args)
4. String r = "-";
5. char[] c = {"a", "b", "c", "z"};
6. for(char c1: c)
7. switch (c1) {
8. case "a": r += "a";
9. case "b": r += "b"; break;
10. default: r += "X";
11. case "z": r+= "z";
12. }
13. System. out.println(r);
14. } }
What is the result?
多选题Given:
2. class Super {
3. static String os = "";
4. void doStuff() {os += "super ";}
5. }
6. public class PolyTest extends Super {
7. public static void main(String[] args) {new PolyTest().go(); }
8. void go() {
9. Super s = new PolyTest();
10. PolyTest p = (PolyTest)s;
11. p.doStuff();
12. s.doStuff();
13. p.doPoly();
14. s.doPoly();
15. System.out.println(os);
16. }
17. void doStuff() {os += "over "; }
18. void doPoly() {os += "poly "; }
19. }
What is the result?
多选题Mary创建了一个名为SCHEDULE的表，结构如下： ID NUMBER(9) PK NAME VARCHAR2(25) CLASS_DATE DATE 她将这个表的INSERT权限赋予了您。随后，您向SCHEDULE表中插入了三行数据，但是并未发提交命令。此时Maiy发了如下的命令： SELECT * FROM schedule; 请问在以下的陈述中，哪3个是正确的? A．Mary将能够访问SCHEDULE表 B．Mary将不能访问SCHEDULE表 C．Mary将能够向SCHEDULE表中插入相同的记录 D．Maiy将能够看到您在SCHEDULE表中插入三个记录 E．Mary将不能看到您在SCHEDULE表中插入三个记录 F．Mary将不能向SCHEDULE表中插入相同的记录
多选题在运行RMAN RESTORE CONTROLFILE命令时，RMAN在何处放置旧版控制文件?
多选题Given:
2. import java.util.*;
3. public class MyFriends {
4. String name;
5. MyFriends(String s) {name = s; }
6. public static void main(String[] args) {
7. Set＜MyFriends＞ ms = new HashSet＜MyFriends＞();
8. ms.add(new MyFriends("Bob"));
9. System.out.print(ms + " ");
10. ms.add(new MyFriends("Bob"));
11. System.out.print(ms + " ");
12. ms.add(new MyFriends("Eden"));
13. System.out.print(ms + " ");
14. }
15. public String toString() {return name; }
16. }
What is the most likely result?
多选题Given this code in a method:
4. Integer[] [] la = {{1,2}, {3,4,5}};
5. Number[] na = la[1];
6. Number[] na2 = (Number[])la[0];
7. Object o = na2;
8. la[1] = (Number[])o;
9. la[0] = (Integer[])o;
What is the result? (Choose all that apply.)
多选题数据库的BI_HR表空间所在的磁盘受到损坏，但是闪回恢复区中包含映像副本和所有需要的重做日志文件。请按正确顺序排列以下RMAN命令，以便成功地恢复BI_HR表空间：
1．recover tablespace bi_hr;
2．sql "alter tablespace bi_hr online";
3．switch tablespace bi_hr to copy;
4．sql "alter tablespace bi_hr offline immediate";
多选题请看如下的SQL语句： SELECT line_item_id, orderid, product_id FROM line_item; 使用以下的哪个WHERE子句能测试出quantity列是否包含空值(NULL)? A．WHERE quantity=NULL; B．WHERE quantity＜＞NULL; C．WHERE quantity!=NULL; D．WHERE quantity IS NULL;
多选题Given:
3. public class Honcho {
4. static boolean b1 = false;
5. static int z = 7;
6. static Long y;
7. public static void main(String[] args)
8. for(int i = 0; i ＜ 4; i++)
9. go(i);
10. }
11. static void go(int x) {
12. try {
13. if((x == 0)
14. if(x ＜ 2 ^ x ＜ 10) System.out.print("1 ");
15. if((x == 2)
16. if(z ＜= (x + 4)) System.out.print("3 ");
17. }
18. catch (Exception e) {System.out.print("e "); }
19. } }
What is the result?