Re: what is the difference between ROLE clause and IN ROLE clause for CREATE USER statement ?

I think create in role makes the user a member of the specified role. While
create role makes the roles members of this new user group. So it's a
question of which is the container and what is being contained.

On Tue, Sep 1, 2026, 10:16 PM Pierre Forstmann <pierre(dot)forstmann(at)gmail(dot)com>
wrote:

> Hello,
>
> I don't understand the difference even after reading CREATE USER/CREATE
> ROLE documentation.
>
> Here is a scenario that shows a difference with PG 18.6 (built with pgenv):
>
> pierre=# create user ur role pg_maintain;
> CREATE ROLE
> pierre=# create user uri in role pg_maintain;
> CREATE ROLE
> pierre=# \du
> List of roles
> Role name | Attributes
> -----------+------------------------------------------------------------
> pierre | Superuser
> postgres | Superuser, Create role, Create DB, Replication, Bypass RLS
> ur |
> uri |
>
> pierre=# \l
> List of databases
> Name | Owner | Encoding | Locale Provider | Collate |
> Ctype | Locale | ICU Rules | Access privileges
>
> -----------+----------+----------+-----------------+-------------+-------------+--------+-----------+-----------------------
> pierre | pierre | UTF8 | libc | en_US.UTF-8 |
> en_US.UTF-8 | | |
> postgres | postgres | UTF8 | libc | en_US.UTF-8 |
> en_US.UTF-8 | | |
> template0 | postgres | UTF8 | libc | en_US.UTF-8 |
> en_US.UTF-8 | | | =c/postgres +
> | | | | | |
> | | postgres=CTc/postgres
> template1 | postgres | UTF8 | libc | en_US.UTF-8 |
> en_US.UTF-8 | | | =c/postgres +
> | | | | | |
> | | postgres=CTc/postgres
> (4 rows)
>
>
> pierre(at)alma:~$ vacuumdb -U ur
> vacuumdb: vacuuming database "pierre"
> WARNING: permission denied to vacuum "pg_proc", skipping it
> WARNING: permission denied to vacuum "pg_attribute", skipping it
> WARNING: permission denied to vacuum "pg_description", skipping it
> WARNING: permission denied to vacuum "pg_collation", skipping it
> WARNING: permission denied to vacuum "pg_statistic", skipping it
> WARNING: permission denied to vacuum "pg_type", skipping it
> WARNING: permission denied to vacuum "pg_class", skipping it
> WARNING: permission denied to vacuum "pg_rewrite", skipping it
> WARNING: permission denied to vacuum "pg_operator", skipping it
> WARNING: permission denied to vacuum "pg_depend", skipping it
> WARNING: permission denied to vacuum "sql_features", skipping it
> WARNING: permission denied to vacuum "pg_amop", skipping it
> WARNING: permission denied to vacuum "pg_constraint", skipping it
> WARNING: permission denied to vacuum "pg_amproc", skipping it
> WARNING: permission denied to vacuum "pg_ts_config_map", skipping it
> WARNING: permission denied to vacuum "pg_index", skipping it
> WARNING: permission denied to vacuum "pg_init_privs", skipping it
> WARNING: permission denied to vacuum "pg_opclass", skipping it
> WARNING: permission denied to vacuum "pg_aggregate", skipping it
> WARNING: permission denied to vacuum "pg_cast", skipping it
> WARNING: permission denied to vacuum "pg_opfamily", skipping it
> WARNING: permission denied to vacuum "pg_conversion", skipping it
> WARNING: permission denied to vacuum "pg_namespace", skipping it
> WARNING: permission denied to vacuum "sql_implementation_info", skipping
> it
> WARNING: permission denied to vacuum "pg_am", skipping it
> WARNING: permission denied to vacuum "pg_language", skipping it
> WARNING: permission denied to vacuum "pg_authid", skipping it
> WARNING: permission denied to vacuum "pg_database", skipping it
> WARNING: permission denied to vacuum "pg_tablespace", skipping it
> WARNING: permission denied to vacuum "pg_auth_members", skipping it
> WARNING: permission denied to vacuum "pg_shdescription", skipping it
> WARNING: permission denied to vacuum "pg_ts_config", skipping it
> WARNING: permission denied to vacuum "pg_ts_dict", skipping it
> WARNING: permission denied to vacuum "pg_ts_parser", skipping it
> WARNING: permission denied to vacuum "pg_ts_template", skipping it
> WARNING: permission denied to vacuum "pg_extension", skipping it
> WARNING: permission denied to vacuum "pg_range", skipping it
> WARNING: permission denied to vacuum "sql_parts", skipping it
> WARNING: permission denied to vacuum "sql_sizing", skipping it
> WARNING: permission denied to vacuum "pg_shdepend", skipping it
> WARNING: permission denied to vacuum "pg_transform", skipping it
> WARNING: permission denied to vacuum "pg_sequence", skipping it
> WARNING: permission denied to vacuum "pg_subscription", skipping it
> WARNING: permission denied to vacuum "pg_publication", skipping it
> WARNING: permission denied to vacuum "pg_publication_namespace",
> skipping it
> WARNING: permission denied to vacuum "pg_publication_rel", skipping it
> WARNING: permission denied to vacuum "pg_subscription_rel", skipping it
> WARNING: permission denied to vacuum "pg_foreign_data_wrapper", skipping
> it
> WARNING: permission denied to vacuum "pg_foreign_server", skipping it
> WARNING: permission denied to vacuum "pg_policy", skipping it
> WARNING: permission denied to vacuum "pg_replication_origin", skipping it
> WARNING: permission denied to vacuum "pg_default_acl", skipping it
> WARNING: permission denied to vacuum "pg_inherits", skipping it
> WARNING: permission denied to vacuum "pg_seclabel", skipping it
> WARNING: permission denied to vacuum "pg_shseclabel", skipping it
> WARNING: permission denied to vacuum "pg_user_mapping", skipping it
> WARNING: permission denied to vacuum "pg_trigger", skipping it
> WARNING: permission denied to vacuum "pg_event_trigger", skipping it
> WARNING: permission denied to vacuum "pg_statistic_ext_data", skipping it
> WARNING: permission denied to vacuum "pg_statistic_ext", skipping it
> WARNING: permission denied to vacuum "pg_enum", skipping it
> WARNING: permission denied to vacuum "pg_attrdef", skipping it
> WARNING: permission denied to vacuum "pg_largeobject_metadata", skipping
> it
> WARNING: permission denied to vacuum "pg_foreign_table", skipping it
> WARNING: permission denied to vacuum "pg_parameter_acl", skipping it
> WARNING: permission denied to vacuum "pg_db_role_setting", skipping it
> WARNING: permission denied to vacuum "pg_partitioned_table", skipping it
> WARNING: permission denied to vacuum "pg_largeobject", skipping it
> pierre(at)alma:~$ vacuumdb -U uri
> vacuumdb: vacuuming database "pierre"
> pierre(at)alma:~$
>
>
> Thanks.
>
>
>
>