多选题Which three are DATETIME data types that can be used when specifying column definitions?（）ATIMESTAMPBINTERVAL MONTH TO DAYCINTERVAL DAY TO SECONDDINTERVAL YEAR TO MONTHETIMESTAMP WITH DATABASE TIMEZONE

第1题：

Which two statements are true regarding the USING clause in table joins?（）

• A、It can be used to join a maximum of three tables 
• B、It can be used to restrict the number of columns used in a NATURAL join 
• C、It can be used to access data from tables through equijoins as well as nonequijoins 
• D、It can be used to join tables that have columns with the same name and compatible data types

第2题：

The RMAN BACKUP command using the DELETE INPUT option can be used with which three types of files？ （）

• A、data files
• B、backup sets
• C、control files
• D、archived redo log files

第3题：

第4题：

You are creating a form that will access an Oracle8 database. On which three sources can you base a data block?（）

• A、BFILE 
• B、REF column 
• C、Object table 
• D、Column object 
• E、INSTEAD-OF trigger

第5题：

You work as a database administrator for Supportcenter.cn. You are using Recovery Manager （RMAN） to perform backups in your databases. Which four backup operations can be performed using RMAN？（）

• A、A backup of the target database when it is mounted
• B、A backup of online redo log files when the database is open
• C、A backup of only used data blocks in the file beingbeingbackup up
• D、A backup of online， read/write data files when the database is open
• E、A backup of only those data blocks that have changed since a previous backup
• F、A backup of online， read/write data files when the database is in the NOMOUNT state.

第6题：

Which of the following constraint types can be used to ensure the value of an INTEGER column references only positive values?（）

• A、Unique
• B、Check
• C、Referential
• D、Informational

第7题：

For an incomplete recovery， which four backup types can be used by Recovery Manager （RMAN） to restore data files？ （）

• A、RMAN image copies
• B、RMAN database backups
• C、RMAN tablespace backups
• D、user­managed backups placed in the flash recovery area
• E、user­managed backups that have been cataloged with RMAN
• F、user­managed data file backups for which the full path name is specified

第8题：

第9题：

Which three tasks can be performed using regular expression support in Oracle Database 10g？（）

• A、 it can be used to concatenate two strings.
• B、 it can be used to find out the total length of the string.
• C、 it can be used for string manipulation and searching operations.
• D、 it can be used to format the output for a column or expression having string data.
• E、 it can be used to find and replace operations for a column or expression having string data.

第10题：

Which three are DATETIME data types that can be used when specifying column definitions?（）

• A、TIMESTAMP
• B、INTERVAL MONTH TO DAY
• C、INTERVAL DAY TO SECOND
• D、INTERVAL YEAR TO MONTH
• E、TIMESTAMP WITH DATABASE TIMEZONE