多项选择题
A.After the COPY command.
B.After adding a data file in the target database.
C.After adding a tablespace in the target database.
D.After adding a tablespace in the catalog database.
E.After dropping a data file in the catalog database.
F.After running SQL Loader to load a large amount of data.
多项选择题 Which three statements about direct path exports are true？（）
多项选择题 Some data storage and transfer media have fixed-length physical records. When the data records are short， more then one can be stored in a single， physical record to use the storage space efficiently. Consider this data： 1119 Smith 1120 Yvonne 1121 Albert 1130 Thomas Which two statements can you use to load the data into the EMP table？（）
单项选择题 Data file DF1 belongs to tablespace TS1.，and the database is in ARCHIVELOG mode. You did an incomplete recover in the following steps： 1. Take data file DF1 offline. 2. Copy a backup copy of DF1 into the current DF1 location. 3. Execute RECOVER DATAFILE UNTIL TIME sometime in the past. 4. Bring DF1 online. 5. Execute ALTER DATABASE OPEN RESETLOGS. To guarantee that the database is recoverable in the future， what is the least amount of work needed？（）