创建数据库bbb且owner为用户b:
postgres9.6@[local]:5432 postgres# create database bbb owner b; CREATE DATABASE Time: 259.099 ms
默认情况下使用用户c也可以连接数据库bbb:
postgres9.6@[local]:5432 postgres# /c bbb c You are now connected to database "bbb" as user "c".
回收public的connect on database bbb权限:
c@[local]:5432 bbb# /c postgres postgres9.6 You are now connected to database "postgres" as user "postgres9.6". postgres9.6@[local]:5432 postgres# revoke connect on database bbb from public; REVOKE Time: 2.088 ms
此时用户c没有了连接数据库bbb的权限:
postgres9.6@[local]:5432 postgres# /c bbb c FATAL: permission denied for database "bbb" DETAIL: User does not have CONNECT privilege. Previous connection kept
但bbb数据库的owner用户b可以连接数据库:
postgres9.6@[local]:5432 postgres# /c bbb b You are now connected to database "bbb" as user "b". b@[local]:5432 bbb#
此种情况下超级用户也可以连接该数据库:
b@[local]:5432 bbb# /c bbb postgres9.6 You are now connected to database "bbb" as user "postgres9.6". postgres9.6@[local]:5432 bbb# postgres9.6@[local]:5432 bbb# /du List of roles Role name | Attributes | Member of -------------+------------------------------------------------------------+----------- a | | {} b | | {} c | | {} postgres9.6 | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
另外一种方法:从pg_hba.conf中限定:
# TYPE DATABASE USER ADDRESS METHOD # "local" is for Unix domain socket connections only local all all trust # IPv4 local connections: host all all 127.0.0.1/32 trust ... # host all all 0.0.0.0/0 md5
补充:Postgres限制每个用户只能连接指定数量的session,防止服务器资源紧张
限制每个用户只能连接指定数量的session,防止服务器资源紧张
(1)创建测试用户test:
highgo=#create user test; CREATEROLE highgo=#/du List of roles Role name | Attributes | Member of -----------+------------------------------------------------+---------- highgo | Superuser, Create role, Create DB, Replication | {} test | | {}
(2)设置仅允许用户test使用一个连接
highgo=#ALTER ROLE test CONNECTION LIMIT 1; ALTERROLE
(3)在session 1中使用test用户连接highgo数据库
highgo=>/c highgo test Youare now connected to database "highgo" as user "test". highgo=>
(4)在session 2中也使用test用户连接highgo数据库,会出现如下错误:
highgo=#/c highgo test 致命错误: 由角色"test"发起的连接太多了 Previousconnection kept
(5)查询用户test链接限制
highgo=>SELECT rolconnlimit FROM pg_roles WHERE rolname = 'test'; rolconnlimit -------------- 1 (1row)
以上为个人经验,希望能给大家一个参考,也希望大家多多支持云图网。如有错误或未考虑完全的地方,望不吝赐教。
原创文章,作者:bd101bd101,如若转载,请注明出处:https://blog.ytso.com/tech/database/232919.html