在Access中，条件"性别＝"女"AND工资＞2000"的含义是指（）。

A、性别为女，并且工资大于2000的记录

B、性别为女，或者工资大于2000的记录

C、性别为女，并非工资大于2000的记录

D、性别为女或者工资大于2000的，且二者只选其一的记录

进程监视进程（PMON）的作用是什么？

Examine the following command: CREATE TABLE (prod_id number(4), Prod_name varchar2 (20), Category_id number(30), Quantity_on_hand number (3) INVISIBLE); Which three statements are true about using an invisible column in the PRODUCTS table?（）

The %ROWTYPE attribute declarations in PL/SQL to access a row will not display the invisible column in the output.

The DESCRIBE commands in SQL *Plus will not display the invisible column in the output.

Referential integrity constraint cannot be set on the invisible column.

The invisible column cannot be made visible and can only be marked as unused.

A primary key constraint can be added on the invisible column.

Which configuration command prevents a client from establishing multiple PPPoE connections from a single workstation?（）

A、sessions

B、sa-validate

C、split-horizon

D、duplicate-protection

You performed an incremental level 0 backup of a database: RMAN > BACKUP INCREMENTAL LEVEL 0 DATABASE; To enable block change tracking after the incremental level 0 backup, you issued this command: SQL > ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE ‘ /mydir/rman_change_track.f’; To perform an incremental level 1 cumulative backup, you issued this command: RMAN> BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE; Which three statements are true?（）

Backup change tracking will sometimes reduce I/O performed during cumulative incremental backups.

The change tracking file must always be backed up when you perform a full database backup.

Block change tracking will always reduce I/O performed during cumulative incremental backups.

More than one database block may be read by an incremental backup for a change made to a single block.

The incremental level 1 backup that immediately follows the enabling of block change tracking will not read the change tracking file to discover changed blocks.

How would an AIX administrator find information regarding smit menu definitions （）

A、Use ODM commands

B、In the /smit.log file

C、In the /etc/environment file

D、In the/usr/lib/smit/menu.cfg file