![]() This is very useful if you're reaching a connection limit and you want to just go and stop some sessions. Superuser reserved connections are a way of being able to connect to the database, even when all the connections have run out. If you're a superuser, you have access to what Postgres calls, superuser_reserved_connections. This is another aspect of how superuser and “almost superuser” are different. The other thing I want to mention is that Postgres 16 introduced the reserved_connections setting. In addition to this, there are a few other improvements, but the important restriction right now is that if you want to CREATE SUBSCRIPTION or CREATE EVENT TRIGGER, those still do require actual superuser access.ĬREATE SUBSCRIPTION or CREATE EVENT TRIGGER still require actual superuser access. This is going to be very useful if you have a lot of users, for example: imagine you create different database users for an RLS-based setup, and so in situations like that, it's going to be really useful to just manage those users more easily. That sets up a system where you have almost superuser that's able to access all the other roles, but it doesn't have to have actual superuser. ![]() In Postgres 16, there is this new "createrole_self_grant" option, which, automatically when you're creating a new role grants it back to the user that was creating that role. Previously, you could already grant a role to yourself, and through that be able to do SET ROLE on it, but it gets quite tedious when you're creating a bunch of users. When I'm the superuser, I'm able to access anything in the system, modify anything in the system, and through that administer the system. This, as Robert notes, is really the core of a superuser experience. It's essentially the same as being able to SET ROLE to any user. You can access a table that's not owned by yourself. If you are superuser you can access other roles' objects, which is very useful. There are also more restrictions around settings like CREATEDB, REPLICATION or BYPASSRLS to make sure that a CREATEROLE user actually has permissions to do that. If you have ADMIN OPTION on another role and you have CREATEROLE privileges, then you can modify that role. ![]() Instead, what they need is the ADMIN OPTION setting. CREATEROLE no longer can hand out memberships in other roles without restriction. What all the cloud providers have done is, they've patched it out and they've modified this because it would otherwise be a security problem for them. If you have CREATEROLE on a regular Postgres database, it's essentially a superuser. And this is not the only way of doing it, but this lets you run something as the postgres user on the operating system side, which ultimately lets you get superuser. When you have CREATEROLE in a standard Postgres, and you're not in a patched version of Postgres, then CREATEROLE is essentially something like superuser.Īnd the reason is, amongst CREATEROLE being able to modify other users without restriction in current releases and CREATEROLE type roles being able to, for example, set the connection limit or change the password for other roles, they can also grant people the pg_execute_server_programs role. CREATEROLE in Postgres 16įirst of all, Robert addresses the impact of having CREATEROLE. Postgres 16 brings a better way of doing something like a RDS superuser, but brings it into core Postgres and adds a few additional improvements that are not there today on your regular Postgres databases in the cloud. The reason that the AWS team added this was because they did not want to have people accessing the operating system on the database server directly, but rather wanted to give folks a couple of privileges that regular roles don't have. The most common example that you might be familiar with is the rds_superuser role in Amazon RDS and Aurora, which essentially pretends to be a superuser, but it's really not. What Robert mentions in his article is that some people have actually hacked the Postgres source code to do this in earlier releases! ![]() It's really hard to make this work in existing Postgres. , there isn't really a good way of achieving the benefits of a superuser without giving full access to the operating system account. You cannot make a role that can perform ordinary administration tasks, but cannot break into the operating system user account, the one that the Postgres server runs as. We'll start with this blog post by Robert Haas who has committed a few improvements to the Postgres 16 branch that reduced the need for using a superuser role in Postgres.Īs Robert mentions, there isn't really a good way of achieving the benefits of a superuser without giving full access to the operating system account. Let's jump right in! The superuser role in Postgres What we have discussed in this episode of 5mins of Postgres.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |