用户维护
（1）创建用户
CREATE USER suntx IDENTIFIED BY "suntx"
DEFAULT TABLESPACE "SUNTX" 
TEMPORARY TABLESPACE "SUNTX_TEMP" 
PROFILE DEFAULT
QUOTA UNLIMITED ON "SUNTX";
（2）给用户赋权
2. 运行以下命令，对用户赋权；
grant execute on dbms_lock to suntx;
grant create any directory to suntx;
GRANT CONNECT TO suntx;
GRANT RESOURCE TO suntx;
create directory DUMP_DIR as '/app/sunline/db';
create directory BACKUP_DUMP_DIR as '/app1/backup/week/exp'
grant read,write on directory DUMP_DIR to suntx;
grant create synonym  to suntx;


grant execute on dbms_lock to sunstg;
grant connect to SUNSTG;
grant resource to SUNSTG;
-- Grant/Revoke system privileges 
grant create database link to SUNSTG;
grant create procedure to SUNSTG;
grant create sequence to SUNSTG;
grant create table to SUNSTG;
grant create trigger to SUNSTG;
grant create view to SUNSTG;
grant debug any procedure to SUNSTG;
grant debug connect session to SUNSTG;
grant create synonym  to suntx;
grant unlimited tablespace to SUNSTG;