select * from tab;
desc <表名>;
select * from user_ind_columns;
select column_name from user_ind_columns where table_name = '<表名>';
select username from user_users;
select * from NLS_DATABASE_PARAMETERS where PARAMETER = 'NLS_NCHAR_CHARACTERSET';
exp "<username>/<password> file=exp01.dmp tables=(JOB, TOKUIDB, TOUR_JOHO)" imp "<username>/<password> file=exp01.dmp tables=(JOB, TOKUIDB, TOUR_JOHO)"