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postgres9.6@[local]:5432 postgres# create database bbb owner b;CREATE DATABASETime: 259.099 ms |
默认情况下使用用户c也可以连接数据库bbb：
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postgres9.6@[local]:5432 postgres# \c bbb cYou are now connected to database "bbb" as user "c". |
回收public的connect on database bbb权限：
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c@[local]:5432 bbb# \c postgres postgres9.6You are now connected to database "postgres" as user "postgres9.6".postgres9.6@[local]:5432 postgres# revoke connect on database bbb from public;REVOKETime: 2.088 ms |
此时用户c没有了连接数据库bbb的权限：
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postgres9.6@[local]:5432 postgres# \c bbb cFATAL: 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：
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postgres9.6@[local]:5432 postgres# \c bbb bYou 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：
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b@[local]:5432 bbb# \c bbb postgres9.6You 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：
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# TYPE DATABASE USER ADDRESS METHOD# "local" is for Unix domain socket connections onlylocal 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:
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highgo=#create user test;CREATEROLEhighgo=#\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
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highgo=#ALTER ROLE test CONNECTION LIMIT 1;ALTERROLE |
（3）在session 1中使用test用户连接highgo数据库
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highgo=>\c highgo testYouare 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：
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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
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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服务器之家。如有错误或未考虑完全的地方，望不吝赐教。
原文链接：https://blog.csdn.net/lk_db/article/details/88952602
