创建用户：
sqlplus /nolog
conn / as sysdba;
create user username identified by password
greant dba to username;
select * from user_sys_privs; 查看当前用户所有权限
select * from user_tab_prive; 查看当前用户对表的权限
1、创建
sys:系统管理员，最高权限
system:本地管理员，次高权限
scott:普通用户，默认密码tiger
2、登陆
sqlplus / as sysdba； 登陆sys账户
sqlplus sys as sysdba；
3、管理用户
alert user scott identified by tiger； 修改密码
4、创建表空间
create tablespace name datafile 'd:\a.dbf' size 100m autoextend on next 50m maxsize 2000m extent management local;
5、删除表空间
drop tablespace name including contents and datafiles
6、创建表空间内的用户
create user username identified by password default tablespace name;
grant connect,resource,dba to username;
7、授权用户使用表空间
alter user name quota unlimited on tablespacename;
8、删除用户
drop user name cascade;