多选题如果需要创建多路复用备份集，那么使用一个BACKUP命令最多可以为每个备份段创建多少个副本?

多选题完整恢复不重要的数据文件时，下面的哪些步骤不是必需的?

多选题Given: 2. public class Toolbox { 3. static Toolbox st; 4. public static void main(String[] args) { 5. new Toolbox().go(); 6. // what"s eligible? 7. } 8. void go() { 9. MyInner in = new MyInner(); 10. Integer i3 = in.doInner(); 11. Toolbox t = new Toolbox(); 12. st = t; 13. System.out.println(i3); 14. } 15. class MyInner { 16. public Integer doInner() {return new Integer(34); 17. } 18. } When the code reaches line 6, which are eligible for garbage collection? (Choose all that apply.)

多选题以下是学生(STUDENT)表所包含的全部列的定义： ID NUMBER(9) PK LAST_NAME VARCHAR2(25) FIRST_NAME VARCHAR2(25) ENROLL_DATE DATE 请看如下的SQL脚本(语句)，应该怎样修改才可以使它运行? ACCEPT id 'Please enter the student id: ' SELECT id, last_name, first_name, enroll_date FROM student WHERE id=&id / A．修改ACCEPT命令 B．在SELECT子句中添加一列 C．在ACCEPT命令中定义一个数据类型 D．将单引号改成双引号

多选题使用下面的语句创建了一个新用户： SQL＞grant connect, resource 2＞to c##bob identified by bob container=all; Grant succeeded. SQL＞connect c##bob/bob; Connected. SQL＞select pdb_id, pdb_name, con_id from cdb_pdbs; no rows selected 既然C##是一个公共用户，为什么在CDB_PDBS中看不到任何行?

多选题请看以下创建表的语句： CREATE TABLE customer ( customer_id NUMBER, company_id VARCHAR2(30), contact_name VARCHAR2(30), contact_title VARCHAR2(20), address VARCHAR2(30), city VARCHAR2(25), region VARCHAR2(10), postal_code VARCHAR2(20), country_id NUMBER DEFAULT 25, phone VARCHAR2(20), fax VARCHAR2(20), credit_limit NUMBER(7, 2)); 以上这个DDL语句将完成如下哪3个商业要求?

多选题创建3个RMAN会话，来备份3个不同的表空间。第三个RMAN会话运行这条命令： run{ set command id to "user bkup"; backup tablespace users; } 对于这个命令，V$SESSION.CLIENT_INFO列的值是什么?

多选题使用如下的SQL语句查询数据库： SELECT bonus FROM salary WHERE bonus BETWEEN 1 AND 250 OR (bonus IN (190, 500, 600) AND bonus BETWEEN 250 AND 500); 请问这个SQL语句将返回如下的哪个值? A．100 B．260 C．400 D．600

多选题应该使用如下哪个命令显示视图PARTS_VU的结构? A．DESCRIBE pats_vu B．DESCRIBE user_views C．SELECT * FROM user_views WHERE lower (view)=parts_vu; D．SELECT * FROM user_objects WHERE lower (user_view)=parts_vu;

多选题在以下有关备份控制文件的论述中，哪两个是正确的? A．应该在创建一个表空间之后备份控制文件 B．如果数据文件是多重映像的(冗余的)，不需要备份控制文件 C．应该在向一个现有的数据库中添加一个数据文件之后备份控制文件 D．使用ALTER DATABASE BACKUP CONTROLFILE TO TRACE语句将创建一个控制文件的操作系统备份

多选题Given: 3. public class Drip extends Thread { 4. public static void main(String[] args) { 5. Thread t1 = new Thread(new Drip()); 6. t1.start(); 7. t1.join(); 8. for(int i = 0; i ＜ 1000; i++) // Loop #1 9. System.out.print(Thread.currentThread() .getName() + " "); 10. } 11. public void run() { 12. for(int i = 0; i ＜ 1000; i++) // Loop #2 13. System.out.print(Thread.currentThread() .getName() + " "); 14. } } Which are true? (Choose all that apply.)

多选题Given the proper import statements and: 23. try { 24. File file = new File("myFile.txt"); 25. PrintWriter pw = new PrintWriter(file); 26. pw.println("line 1"); 27. pw.close(); 28. PrintWriter pw2 = new PrintWriter("myFile.txt"); 29. pw2.println("line 2"); 30. pw2.close(); 31. } catch (IOException e) { } What is the result? (Choose all that apply.)

多选题要创建一个报表，这个报表将显示那些信用限额大于所有客户平均信用限额的客户，应使用如下的哪个查询语句? A．SELECT last_name, first_name FROM customer WHERE credit_limit＞AVG(credit_limit); B．SELECT last_name, first_name, AVG(credit_limit) FROM customer GROUP BY AVG(credit_limit); C．SELECT last_name, firs_name, AVG(credit_limit) FROM customer GROUP BY AVG(credit_limit) HAVING credit_limit＞AVG(credit_limit); D．SELECT last_name, first_name FROM customer WHERE credit_limit＞(SELECT AVG(credit_limit) FROM customer); E．SELECT last_name, first_name FROM customer WHERE credit_limit=(SELECT AVG(credit_limit) FROM customer);

多选题Given two files: 1. package com; 2. public class MyClass { 3. public static void howdy() {System.out.print("howdy "); } 4. public static final int myConstant = 343; 5. public static final MyClass mc = new MyClass(); 6. public int instVar = 42; 7. } 11. import static com. MyClass.*; 12. public class TestImports { 13. public static void main(String[] args) 14. System.out.print(myConstant + " "); 15. howdy(); 16. System.out.print(mc.instVar + " "); 17. System.out.print(instVar + " "); 18. } } What is the result? (Choose ALL that apply.)

多选题在以下有关数据库备份的描述中找到不正确的描述。

多选题在一个SELECT语句中，应该使用WHERE子句来完成以下的哪些工作? A．指定INVENTORY表的位置(地址) B．将MANUFACTURER_ID的值与897898进行比较 C．仅显示MANUFACTURER_ID的值 D．限制SUM(price)函数的输出

多选题现在需要基于一个未知条件来返回数据，应使用以下哪种结构?

多选题见下表SERVICE，如果使用如下的查询语句，第一个显示的是哪一个值?SELECTmachine_idFROMserviceORDERBYtechnician_id,service_date;A．458745B．600252C．687523D．980076

多选题以下是PRODUCT(产品)表和SUPPLIER(供应商)表的结构： 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 SUPPLIER SUPPLIER_ID NUHBER NOT NULL, Primary Key SUPPLIER_NAME VARCHAR2(25) ADDRESS VARCHAR2(30) CITY VARCHAR2(25) REGION VARCHAR2(10) POSTAL_CODE VARCHAR2(11) 评估如下的SQL语句，请问这个语句将完成以下的哪个任务? ALTER TABLE product DISABLE CONSTRAINT supplier_id_fk;

多选题Given the following pseudo-code design for a new accounting system: class Employee maintainEmployeeInfo() connectToRDBMS() class Payroll setStateTaxCodes() findEmployeesByState() class Utilities getNetworkPrinter() Assuming the class and method names provide good definitions of their own functionalities, which are probably true? (Choose all that apply.)