choose two
You plan to upgrade your Oracle Database 9i to Oracle Database 12c.
Which two methods can you use?
A) Perform a direct upgrade by manually running the catctl.pl and catupgrd.sql scripts before issuing the STARTUPUPGRADE command.
B) Upgrade your current database to Oracle Database release 10.2.0.5, and then upgrade to Oracle Database 12c.
C) Perform a direct upgrade by running the Database Upgrade Assistant (DBUA).
D) Perform a rolling upgrade.
E) Install the Oracle Database 12c software, create a new Oracle 12c database, and then use the Oracle Data Pump to import data from the source Oracle 9i database to the target Oracle 12c database.
Answer：BE
(解析：这道题考的升级的内容挺深的，有些内容故意打乱顺序，混淆视听。
A答案应该是先以升级方式启动数据库，然后再执行那两个脚本。
B答案对是因为9i的数据库不能直接升级到12c，需要先升级到10.2.0.5，然后再升级到12c。
C答案就不用说了，肯定不行。
D答案说的比较笼统，没有具体说出升级方式。
E答案是比较清晰的答案，可以把数据库通过导出导入方式进行升级。
来自3组：1015267481)