在Oracle 11gR2环境中，假如用户同时被授予了connect和resource角色后，即可登录数据库创建对象。但是在Oracle 12c中，如果用户只是被授予了这两个角色，可以创建对象，但是无法插入数据。
实验
下面做一个小实验：
Oracle 11g环境：
(1)创建表空间
CREATE TABLESPACE test DATAFILE
'/u01/app/oracle/oradata/bond/test01.dbf' SIZE 5242880
AUTOEXTEND ON NEXT 1310720 MAXSIZE 32767M
LOGGING ONLINE PERMANENT BLOCKSIZE 8192
EXTENT MANAGEMENT LOCAL AUTOALLOCATE DEFAULT
NOCOMPRESS SEGMENT SPACE MANAGEMENT AUTO;
(2)创建用户并授权
create user test identified by "test" default tablespace test;
grant resource,connect to test;
(3)创建对象并插入数据
[oracle@bond ~]$ sqlplus test/test
SQL*Plus: Release 11.2.0.4.0 Production on Sun Aug 18 13:56:26 2019
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
SQL> create table t_dict as
2 select * from dict where rownum <=100;
Table created.
插入数据成功！
Oracle 12c环境
(1)创建表空间
CREATE TABLESPACE test DATAFILE
'/u01/app/oracle/oradata/bond/test01.dbf' SIZE 5242880
AUTOEXTEND ON NEXT 1310720 MAXSIZE 32767M
LOGGING ONLINE PERMANENT BLOCKSIZE 8192
EXTENT MANAGEMENT LOCAL AUTOALLOCATE DEFAULT
NOCOMPRESS SEGMENT SPACE MANAGEMENT AUTO;
(2)创建用户并授权
create user test identified by "test" default tablespace test;
grant resource,connect to test;
(3) 建对象并插入数据
[oracle@bond ~]$ sqlplus test/test
SQL*Plus: Release 12.2.0.1.0 Production on Fri Sep 6 19:53:16 2019
Copyright (c) 1982, 2016, Oracle. All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
SQL> create table t_dict as
2 select * from dict where rownum <=100;
select * from dict where rownum <=100
*
ERROR at line 2:
ORA-01950: no privileges on tablespace 'TEST'
插入数据失败。
原因分析
对比11g和12c的角色权限及用户权限可知，当用户被授予connect和resource权限后，11g默认会授予用户UNLIMITED TABLESPACE权限，而12c并没有默认授予该权限。
查询官网得知，11g R2的这种现象貌似是一个bug，而12c修复了这个bug。官网解释如下：
The UNLIMITED TABLESPACE system privilege will be removed from the RESOURCE role in a future Oracle Database release (reference Bug 7614645).
思考
既然12c不能像11g那样直接授予用户connect和resource权限即可使用，那么该怎么去创建用户并分配权限呢？
以下给个创建普通用户的示例：
CREATE TABLESPACE test DATAFILE
'/u01/app/oracle/oradata/bond/test01.dbf' SIZE 5242880
AUTOEXTEND ON NEXT 1310720 MAXSIZE 32767M
LOGGING ONLINE PERMANENT BLOCKSIZE 8192
EXTENT MANAGEMENT LOCAL AUTOALLOCATE DEFAULT
NOCOMPRESS SEGMENT SPACE MANAGEMENT AUTO;
CREATE TEMPORARY TABLESPACE test_temp TEMPFILE
'/u01/app/oracle/oradata/bond/test_temp01.dbf' SIZE 33554432
AUTOEXTEND ON NEXT 655360 MAXSIZE 32767M
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1048576;
create user test identified by "test"
default tablespace test
quota 30G on test
temporary tablespace test_temp;