Oracle Commands

1. select   table_name   from   user_tables;     //当前用户的表   
    select   table_name   from   all_tables;     //所有用户的表
    select   table_name   from   dba_tables;       //包括系统表
    select   table_name   from   dba_tables   where   owner='用户名'

    select * from tab;

    select * from cat;

2.backup database:

set NLS_LANG=AMERICAN_AMERICA.al32UTF8
set nls_nchar_characterset=american_america.al16utf16
exp dev_idex_m19/p@idex40 file=d:/[e-mail] log=d:/[e-mail]

write a bat file.