I am the new of Oracle , and that i need to learn more about it . But as you know , here is the company , not the school , you just stady by yourself , and no one can help you a lots .

So that , for the work , i need to learn how to backup our databases .

Do it like that ,you want to backup all of the database files, you can do it like that :

expdp username/password schemas=XXX dumpfile=xxx.dump directory=exp_dir 

If you want to backup one time data and one table , you can add the condition to the order, for example:

expdp username/password dumpfil=XXX directory=exp_dir tables=table01 query=\""where time\<to_char\(\"2014\-10\-01\" , "yyyy\-MM\-dd"\)\""

Imput the data to the database ,

impdp username/password schemas=XXX directory=exp_dir dumpfile=XXX.dump logfile=XXX.log

oracle 数据导入导出