集合A={1,2,…,10}上的关系R={(x,y):x,y∈A且x+y=10},则R的性质为( )。
A、自反的
B、对称的
C、传递的,对称的
D、传递的
Which CLI command copies a file called 4-0-0.rel from FTP server userpc to the router?()
A、get 4-0-0.rel userpc:4-0-0.rel
B、get userpc:4-0-0.re l4-0-0.rel
C、copy 4-0-0.rel userpc:4-0-0.rel
D、copy userpc:4-0-0.rel 4-0-0.rel
欧洲城市的城徽中,用黑熊作为城徽的是()。
A、瑞士伯尔尼
B、德国柏林
C、华沙
D、布拉格
E、意大利
简述产品服务策略?
在Windows系统的资源管理器中,如果某文件夹图标前有“+”表示该文件夹()。
A、含有文件
B、含有子文件
C、是桌面上的应用程序
D、不含有子文件夹
Your database operates in ARCHIVELOG mode. The redo log files are not multiplexed and one of the online redo logs is missing. The missing redo log sequence, 230, is not archived, and it contained information from 10:35 a.m. onwards. The current time is 11:00 a.m. Because of a disk crash, you executed the following command to perform an incomplete recovery: RMAN> RUN { 2> SET UNTIL SEQUENCE 230 THREAD 1; 3> ALTER DATABASE MOUNT; 4> RESTORE DATABASE; 5> RECOVER DATABASE; 6> ALTER DATABASE OPEN RESETLOGS; 7> }; With reference to this scenario, which statement is true?()
A、RMAN recovers up to log sequence 230, but not including 230.
B、RMAN returns an error because the log sequence number mentioned in the command should be 229.
C、RMAN returns an error because the log sequence number mentioned in the command may never be missing.
D、RMAN recovers up to and including log sequence 229 but then returns an error because log sequence 230 is missing.