[单选] All IBM TS7650 ProtecTIER Deduplication Appliances supports emulation of up to how manyvirtual libraries, virtual tape drives, and virtual tape cartridges?（）

假山分层施工工艺流程 You are working in an online transaction processing （OLTP） environment. You used the FLASHBACK TABLE command to flash back the CUSTOMERS table. Before executing the FLASHBACK TABLE command， the System Change Number （SCN） was 663571. After flashing back the CUSTOMERS table，you realize that the table is not in the correct state and the resultant changes are not what you had desired. So， you need to reverse the effects of the FLASHBACK TABLE command while ensuring that：  a） No other user data in the database is affected.  b） The operation takes the minimum possible time.  Which option would you choose？（）  use the ROLLBACK command with SCN 663571。 perform Flashback Transaction Query with SCN 663571。 execute the FLASHBACK DATABASE statement to retrieve the CUSTOMERS table as it was at SCN 663571。 execute another FLASHBACK TABLE statement to retrieve the CUSTOMERS table as it was at SCN 663571。 You want to create a role to meet these requirements： 1. The role is to be protected from unauthorized usage. 2. The password of the role is not to be embedded in the application source code or stored in a table. method would you use to restrict enabling of such roles（） Create the role with external authentication.。 Create the role as a secure application role.。 Create the role as a password-protected role.。 Create a role and use Fine-Grained Access Control （FGAC） to secure the role。 某办公楼幕墙工程28层，正立面为单元式玻璃幕墙5600m2，其他部位为石材12000m2和金属幕墙4700m2、明框玻璃幕墙6000m2，采用钢化中空玻璃，幕墙的开启扇采用隐框玻璃上悬窗。 施工过程中，发生了如下事件： 事件一：单元式玻璃组件采用之江牌硅酮结构密封胶。安装过程中金属扣盖采用白云牌硅酮耐候密封胶。层问防火封堵采用白云牌硅酮耐候密封胶。避雷接地每4层做均压环与连接主体接地体有效连接。 事件二：玻璃幕墙工程质量验收划分为11个检验批，每个检验批每500m2抽查一处，每处1Om2。检测报告的石材弯曲强度为7.OMPa，吸水率为1%。石材幕墙采用的铝合金挂件厚度为3.Omm。监理工程师认为存在错误，责令整改。石材的弯曲强度和吸水率应为多少？石材幕墙采用铝合金挂件厚度正确应为多少？ View the Exhibit for some of the current parameter settings. A user logs in to the HR schema and issues the following commands: SQL> CREATE TABLE emp (empno NUMBER(3), ename VARCHAR2(20), sal NUMBER(8,2)); SQL> INSERT INTO emp(empno,ename) VALUES(1,'JAMES'); At this moment, a second user also logs in to the HR schema and issues the following command: SQL> ALTER TABLE emp MODIFY sal NUMBER(10,2); What happens in the above scenario?（） The second user's session immediately produces the resource busy error.。 The second user's command executes successfully.。 The second user's session waits for a time period before producing the resource busy error.。 A deadlock is created.。 All IBM TS7650 ProtecTIER Deduplication Appliances supports emulation of up to how manyvirtual libraries, virtual tape drives, and virtual tape cartridges?（）