多选题以下的哪个CREATE RESTORE POINT命令将保留由初始化参数CONTROL_FILE_RECORD_KEEP_TIME指定的过去的还原时间点?
多选题Given:
2. class Explode {
3. static String s = "";
4. static {s += "sb1 "; }
5. Explode() {s += "e "; }
6. }
7. public class C4 extends Explode {
8. C4() {
9. s += "c4 ";
10. new Explode();
11. }
12. static {
13. new C4();
14. System.out.print(s);
15. }
16. {s += "i ";}
17. public static void main(String[] args) { }
18. }
And given the command-line invocation "java C4", what is the result?
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;
多选题当数据库开启时，如果需要，Oracle会进行实例恢复，请问以下的哪个Oracle后台进程开启会检查数据的一致性? A．DBWn B．LGWR C．SMON D．PMON
多选题Given:
1. public class WeatherTest {
2. static Weather w;
3. public static void main(String[] args) {
4. System.out.print(w.RAINY.count + " " + w. Sunny . count + " ");
5. }
6. }
7. enum Weather {
8. RAINY, Sunny;
9. int count = 0;
10. Weather() {
11. System.out.print("c ");
12. count++;
13. }
14. }
What is the result?
多选题Given:
1. class Locker extends Thread {
2. private static Thread t;
3. public void run() {
4. if (Thread.currentThread() == t) {
5. System.out.print ("1 ");
6. synchronized(t) {doSleep(2000); }
7. System.out.print("2 ");
8. } else {
9. System.out.print ("3 ");
10. synchronized(t) {doSleep(1000); }
11. System.out.print("4 ");
12. }
13. }
14. private void doSleep(long delay) {
15. try {Thread.sleep (delay); } catch(InterruptedException ie) { ; }
16. }
17. public static void main (String args[]) {
18. t = new Locker();
19. t.start();
20. new Locker() .start();
21. } }
Assuming that sleep() sleeps for about the amount of time specified in its argument, and that all other code runs almost instantly, which are true? (Choose all that apply.)
多选题产品(PRODUCT)表的结构如下：
PRODUCT
PRODUCT_ID
NUMBER
NOT NULL, Primary Key
PRODUCT_NAME
VARCHAR2(25)
SUPPLIER_ID
NUMBER
Foreign key to SUPPLIER_ID of the SUPPLIER table
LIST_PRICE
NUMBER(7, 2)
COST
NUMBER(7, 2)
QTY_IN_STOCK
NUMBER
QTY_ON_ORDER
NUMBER
REORDER_LEVEL
NUMBER
REORDER_QTY
NUMBER
如果使用如下的SQL语句，哪个子句将会产生错误?
SELECT supplier_id，AVG(cost)
FROM product
WHERE AVG(list_price)＞60.00
GROUP BY supplier_id
ORDER BY AVG(cost)DESC;
多选题在一个使用了“＜＞”操作符的子查询中可以返回多少个值? A．只能1个 B．最多2个 C．最多10个 D．没有限制
多选题下面的哪些故障是用户错误?
多选题要复制一个数据库，但要最小化源数据库及其所有表空间的停机时间。这类数据库复制的最好方法是什么?
多选题假设登录数据库后，修改INVENTOPY(库存)表。当会话开始之后(连接成功之后)，发出来3个UPDATE语句，然后使用ALTER table语句在这个表上添加了一个列约束。可是正在发COMMIT语句时系统崩溃了，请问以下所做的哪些变化适用于INVENTORY表? A．只有UPFDATE语句 B．只有ALTERTABLE语句 C．UPFDATE语句和ALTER TABLE命令 D．没有
多选题在创建表时，如果定义了一个列的数据类型为VARCHAR2，该列的默认长度是如下的哪一个?
多选题Given:
4. class Account {Long acctNum, password; }
5. public class Banker {
6. public static void main(String[] args) {
7. new Banker() .go();
8. // do more stuff
9. }
10. void go() {
11. Account a1 = new Account();
12. al.acctNum = new Long("1024");
13. Account a2 = a1;
14. Account a3 = a2;
15. a3.password = a1.acctNum.longValue();
16. a2.password = 4455L;
17. } }
When line 8 is reached, which are true? (Choose all that apply.)
多选题Given:
2. public class Hug implements Runnable
3. static Thread t1;
4. static Hold h, h2;
5. public void run() {
6. if(Thread.currentThread() .getId() == t1.getId() h.adjust();
7. else h2.view();
8. }
9. public static void main(String[] args) {
10. h = new Hold();
11. h2 = new Hold();
12. t1 = new Thread(new Hug());
13. t1.start();
14. new Thread(new Hug()).start();
15. } }
16. class Hold {
17. static int x = 5;
18. synchronized void adjust() {
19. System.out.print(x-- + " ");
20. try {Thread.sleep(200); } catch (Exception e) { ; }
21. view();
22. }
23. synchronized void view() {
24. try {Thread.sleep(200); } catch (Exception e) { ; }
25. if(x ＞ 0) adjust();
26. } }
Which are true? (Choose all that apply.)
多选题为什么要使用大对象(LOB)段? A．存储一个ID值 B．存储一段视频 C．存储多个电话号码 D．加快基于一个ID值的查询
多选题Given that FileNotFoundException extends IOException, and given:
2. import java.io.*;
3. public class MacPro extends Laptop {
4. public static void main(String[] args)
5. new MacPro() .crunch();
6. }
7. // insert code here
8. }
9. class Laptop {
10. void crunch() throws IOException { }
11. }
Which method(s), inserted independently at line 7, compile? (Choose all that apply.)
多选题以下是教师(TEACHER)表中的数据： TEACHER ID LAST_NAME FIRST_NAME SUBJECT_ID 88 Tsu Ming HST AMER 70 Smith Ellen HST INDIA 56 Jones Karen 58 Hann Jeff HST CURR 63 Hopewell Mary Elizabeth HST_RELIG 请评估如下的SQL语句，当这个查询语句执行时将首先显示如下的哪条信息? SELECT last_name‖', '‖first_name FROM teacher WHERE subject_id!=NULL ORDER BY last_name; A．Tsu, Ming B．Hann, Jeff C．Smith, Ellen D．不显示任何值
多选题如何验证控制文件是不是多重映像? A．查询动态性能视图V$PARMETER B．查询动态性能视图V$DATABASE C．查询动态性能视图V$CONTROFILE D．使用SHOW PARAMETERS control_files命令 E．查询动态性能视图V$CONTROFILE_RECORD_SECTION
多选题Given:
3. class Employee {
4. private String name;
5. void setName(String n) {name = n;
6. String getName() {return name; }
7. }
8. interface Mungeable {
9. void doMunging();
10. }
11. public class MyApp implements Mungeable {
12. public void doMunging() { ; }
13. public static void main(String[] args) {
14. Employee e = new Employee();
15. e.setName ("bob");
16. System.out.print (e.getName());
17. } }
Which are true? (Choose all that apply.)
多选题Given:
3. class Department {
4. Department getDeptName() {return new Department(); }
5. }
6. class Accounting extends Department {
7. Accounting getDeptName() {return new Accounting(); }
8. // insert code here
13. }
And the following four code fragments:
Ⅰ. String getDeptName(int x) {return "mktg"; }
Ⅱ. void getDeptName(Department d) { ; }
Ⅲ. void getDeptName(long x) throws NullPointerException {
throw new NullPointerException();
}
Ⅳ. Department getDeptName() throws NullPointerException {
throw new NullPointerException();
return new Department();
}
Which are true? (Choose all that apply.)