postgresql影子用户实践场景分析( 三 )

7788 | test | ANALYST | 7566 | 1982-12-09 | 3000.00 |     |   20
7876 | ADAMS | CLERK   | 7788 | 1983-01-12 | 1100.00 |     |   20
1111 | SMITH | CLERK   | 7902 | 1980-12-17 | 800.00 |     |   20
(14 rows)

影子用户创建
如果想让readonly只读用户不在每次 postgres用户在test模式中创建新表后都要手工赋予 grant select on all tables in schema test TO readonly 权限。则需要授予对test默认的访问权限，对于test模式新创建的也生效。
session 1：未来访问test模式下所有新建的表赋权，创建 t5 表。
postgres=# alter default privileges in schema test grant select on tables to readonly ;
ALTER DEFAULT PRIVILEGES
postgres=# create table test.t5 as select * from test.emp;
CREATE TABLE

session 2：查询readonly用户
postgres=> select * from test.t5;
empno | ename | job | mgr | hiredate | sal | comm | deptno
——-+——–+———–+——+————+———+———+——–
7499 | ALLEN | SALESMAN | 7698 | 1981-02-20 | 1600.00 | 300.00 |   30
7521 | WARD | SALESMAN | 7698 | 1981-02-22 | 1250.00 | 500.00 |   30
7566 | JONES | MANAGER | 7839 | 1981-04-02 | 2975.00 |     |   20
7654 | MARTIN | SALESMAN | 7698 | 1981-09-28 | 1250.00 | 1400.00 |   30
7698 | BLAKE | MANAGER | 7839 | 1981-05-01 | 2850.00 |     |   30
7782 | CLARK | MANAGER | 7839 | 1981-06-09 | 2450.00 |     |   10
7839 | KING | PRESIDENT |   | 1981-11-17 | 5000.00 |     |   10
7844 | TURNER | SALESMAN | 7698 | 1981-09-08 | 1500.00 | 0.00 |   30
7900 | JAMES | CLERK   | 7698 | 1981-12-03 | 950.00 |     |   30
7902 | FORD | ANALYST | 7566 | 1981-12-03 | 3000.00 |     |   20
7934 | MILLER | CLERK   | 7782 | 1982-01-23 | 1300.00 |     |   10
7788 | test | ANALYST | 7566 | 1982-12-09 | 3000.00 |     |   20
7876 | ADAMS | CLERK   | 7788 | 1983-01-12 | 1100.00 |     |   20
1111 | SMITH | CLERK   | 7902 | 1980-12-17 | 800.00 |     |   20
(14 rows)

总结：影子用户创建的步骤
–创建影子用户
create user readonly with password ‘postgres’;
–将schema中usage权限赋予给readonly用户,访问所有已存在的表
grant usage on schema test to readonly;
grant select on all tables in schema test to readonly;
–未来访问test模式下所有新建的表
alter default privileges in schema test grant select on tables to readonly ;
文章来源：脚本之家
来源地址：https://www.jb51.net/article/207011.htm
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