创建用户主要关心以下几个方面：
1 认证方式，如密码，外部认证等。通常为密码
2 权限分配与回收       一般用户赋予connect resource 角色
                                              收回默认的unlimited tablespace 权限 避免无限制的使用默认的用户表空间。
                                 其他应用所需权限
3 空间分配      一般为每个用户建立独立的应用相关的tablespace
                       建立tablespace后，在tablespace上给与用户unlimited tablespace权限以使用全部空间。
4 分配给用户默认default tablespace 和 temporary tablespace


相关视图：
dba_sys_privs
dba_ts_quotas;
dba_tablespaces;
dba_users;



1 认证方式，如密码，外部认证等。通常为密码
sys:
create user james identified by james


2 权限分配与回收       一般用户赋予connect resource 角色
                      收回默认的unlimited tablespace 权限 避免无限制的使用默认的用户表空间。
sys@O10G>select * from dba_sys_privs where grantee=‘CONNECT‘;

GRANTEE                          PRIVILEGE                                  ADM
------------------------------ ---------------------------------------- ---
CONNECT                          CREATE SESSION                             NO

sys@O10G>select * from dba_sys_privs where grantee=‘RESOURCE‘;

GRANTEE                          PRIVILEGE                                  ADM
------------------------------ ---------------------------------------- ---
RESOURCE                         CREATE TRIGGER                             NO
RESOURCE                         CREATE SEQUENCE                            NO
RESOURCE                         CREATE TYPE                                NO
RESOURCE                         CREATE PROCEDURE                           NO
RESOURCE                         CREATE CLUSTER                             NO
RESOURCE                         CREATE OPERATOR                            NO
RESOURCE                         CREATE INDEXTYPE                           NO
RESOURCE                         CREATE TABLE                               NO

8 rows selected.

Elapsed: 00:00:00.00
sys@O10G>select * from dba_sys_privs where grantee=‘JAMES‘;

GRANTEE                          PRIVILEGE                                  ADM
------------------------------ ---------------------------------------- ---
JAMES                            UNLIMITED TABLESPACE                       NO

grant connect to james;
grant resource to james;
revoke unlimited tablespace from james;


3 空间分配      一般为每个用户建立独立的应用相关的tablespace
                       建立tablespace后，在tablespace上给与用户unlimited tablespace权限以使用全部空间。

create tablespace james
datafile ‘/export/home/oracle/oradata/james.dbf‘
size 100M
autoextend On
next 10M
maxsize 2048M
extent management local uniform size 128k
segment space management auto;

sys@O10G>alter user james quota unlimited on james;

sys@O10G>select * from dba_ts_quotas where username=‘JAMES‘;

TABLESPACE_NAME USERNAME               BYTES  MAX_BYTES       BLOCKS MAX_BLOCKS DRO
--------------- --------------- ---------- ---------- ---------- ---------- ---
JAMES             JAMES                      0         -1            0           -1 NO

-1 代表unlimited


或者赋予需要的空间
sys@O10G>alter user james quota 10M  on james;

User altered.

sys@O10G>select * from dba_ts_quotas where username=‘JAMES‘;

TABLESPACE_NAME USERNAME               BYTES  MAX_BYTES       BLOCKS MAX_BLOCKS DRO
--------------- --------------- ---------- ---------- ---------- ---------- ---
JAMES             JAMES                      0     10485760            0         1280 NO

4 分配给用户默认default tablespace 和 temporary tablespace

sys@O10G>alter user james
  2  default tablespace james
  3  temporary tablespace temp;

sys@O10G>select username,default_tablespace,temporary_tablespace from dba_users where username=‘JAMES‘;

USERNAME         DEFAULT_TABLESPACE              TEMPORARY_TABLESPACE
--------------- ------------------------------ ------------------------------
JAMES            JAMES                           TEMP

创建用户和分配空间的注意事项