---
sidebar_position: 48
sidebar_label: Access Control and Account Management
---

# Access Control and Account Management

ClickHouse supports access control management based on [RBAC](https://en.wikipedia.org/wiki/Role-based_access_control) approach.

ClickHouse access entities:
- [User account](#user-account-management)
- [Role](#role-management)
- [Row Policy](#row-policy-management)
- [Settings Profile](#settings-profiles-management)
- [Quota](#quotas-management)

You can configure access entities using:

-   SQL-driven workflow.

    You need to [enable](#enabling-access-control) this functionality.

-   Server [configuration files](../operations/configuration-files.md) `users.xml` and `config.xml`.

We recommend using SQL-driven workflow. Both of the configuration methods work simultaneously, so if you use the server configuration files for managing accounts and access rights, you can smoothly switch to SQL-driven workflow.

:::warning
You can’t manage the same access entity by both configuration methods simultaneously.
:::

To see all users, roles, profiles, etc. and all their grants use [SHOW ACCESS](../sql-reference/statements/show.md#show-access-statement) statement.

## Usage {#access-control-usage}

By default, the ClickHouse server provides the `default` user account which is not allowed using SQL-driven access control and account management but has all the rights and permissions. The `default` user account is used in any cases when the username is not defined, for example, at login from client or in distributed queries. In distributed query processing a default user account is used, if the configuration of the server or cluster does not specify the [user and password](../engines/table-engines/special/distributed.md) properties.

If you just started using ClickHouse, consider the following scenario:

1.  [Enable](#enabling-access-control) SQL-driven access control and account management for the `default` user.
2.  Log in to the `default` user account and create all the required users. Don’t forget to create an administrator account (`GRANT ALL ON *.* TO admin_user_account WITH GRANT OPTION`).
3.  [Restrict permissions](../operations/settings/permissions-for-queries.md#permissions_for_queries) for the `default` user and disable SQL-driven access control and account management for it.

### Properties of Current Solution {#access-control-properties}

-   You can grant permissions for databases and tables even if they do not exist.
-   If a table was deleted, all the privileges that correspond to this table are not revoked. This means that even if you create a new table with the same name later, all the privileges remain valid. To revoke privileges corresponding to the deleted table, you need to execute, for example, the `REVOKE ALL PRIVILEGES ON db.table FROM ALL` query.
-   There are no lifetime settings for privileges.

## User Account {#user-account-management}

A user account is an access entity that allows to authorize someone in ClickHouse. A user account contains:

-   Identification information.
-   [Privileges](../sql-reference/statements/grant.md#grant-privileges) that define a scope of queries the user can execute.
-   Hosts allowed to connect to the ClickHouse server.
-   Assigned and default roles.
-   Settings with their constraints applied by default at user login.
-   Assigned settings profiles.

Privileges can be granted to a user account by the [GRANT](../sql-reference/statements/grant.md) query or by assigning [roles](#role-management). To revoke privileges from a user, ClickHouse provides the [REVOKE](../sql-reference/statements/revoke.md) query. To list privileges for a user, use the [SHOW GRANTS](../sql-reference/statements/show.md#show-grants-statement) statement.

Management queries:

-   [CREATE USER](../sql-reference/statements/create/user.md)
-   [ALTER USER](../sql-reference/statements/alter/user.md#alter-user-statement)
-   [DROP USER](../sql-reference/statements/drop.md)
-   [SHOW CREATE USER](../sql-reference/statements/show.md#show-create-user-statement)
-   [SHOW USERS](../sql-reference/statements/show.md#show-users-statement)

### Settings Applying {#access-control-settings-applying}

Settings can be configured differently: for a user account, in its granted roles and in settings profiles. At user login, if a setting is configured for different access entities, the value and constraints of this setting are applied as follows (from higher to lower priority):

1.  User account settings.
2.  The settings of default roles of the user account. If a setting is configured in some roles, then order of the setting application is undefined.
3.  The settings from settings profiles assigned to a user or to its default roles. If a setting is configured in some profiles, then order of setting application is undefined.
4.  Settings applied to all the server by default or from the [default profile](../operations/server-configuration-parameters/settings.md#default-profile).

## Role {#role-management}

Role is a container for access entities that can be granted to a user account.

Role contains:

-   [Privileges](../sql-reference/statements/grant.md#grant-privileges)
-   Settings and constraints
-   List of assigned roles

Management queries:

-   [CREATE ROLE](../sql-reference/statements/create/role.md)
-   [ALTER ROLE](../sql-reference/statements/alter/role.md#alter-role-statement)
-   [DROP ROLE](../sql-reference/statements/drop.md)
-   [SET ROLE](../sql-reference/statements/set-role.md)
-   [SET DEFAULT ROLE](../sql-reference/statements/set-role.md#set-default-role-statement)
-   [SHOW CREATE ROLE](../sql-reference/statements/show.md#show-create-role-statement)
-   [SHOW ROLES](../sql-reference/statements/show.md#show-roles-statement)

Privileges can be granted to a role by the [GRANT](../sql-reference/statements/grant.md) query. To revoke privileges from a role ClickHouse provides the [REVOKE](../sql-reference/statements/revoke.md) query.

## Row Policy {#row-policy-management}

Row policy is a filter that defines which of the rows are available to a user or a role. Row policy contains filters for one particular table, as well as a list of roles and/or users which should use this row policy.

:::warning
Row policies makes sense only for users with readonly access. If user can modify table or copy partitions between tables, it defeats the restrictions of row policies.
:::

Management queries:

-   [CREATE ROW POLICY](../sql-reference/statements/create/row-policy.md)
-   [ALTER ROW POLICY](../sql-reference/statements/alter/row-policy.md#alter-row-policy-statement)
-   [DROP ROW POLICY](../sql-reference/statements/drop.md#drop-row-policy-statement)
-   [SHOW CREATE ROW POLICY](../sql-reference/statements/show.md#show-create-row-policy-statement)
-   [SHOW POLICIES](../sql-reference/statements/show.md#show-policies-statement)

## Settings Profile {#settings-profiles-management}

Settings profile is a collection of [settings](../operations/settings/index.md). Settings profile contains settings and constraints, as well as a list of roles and/or users to which this profile is applied.

Management queries:

-   [CREATE SETTINGS PROFILE](../sql-reference/statements/create/settings-profile.md#create-settings-profile-statement)
-   [ALTER SETTINGS PROFILE](../sql-reference/statements/alter/settings-profile.md#alter-settings-profile-statement)
-   [DROP SETTINGS PROFILE](../sql-reference/statements/drop.md#drop-settings-profile-statement)
-   [SHOW CREATE SETTINGS PROFILE](../sql-reference/statements/show.md#show-create-settings-profile-statement)
-   [SHOW PROFILES](../sql-reference/statements/show.md#show-profiles-statement)

## Quota {#quotas-management}

Quota limits resource usage. See [Quotas](../operations/quotas.md).

Quota contains a set of limits for some durations, as well as a list of roles and/or users which should use this quota.

Management queries:

-   [CREATE QUOTA](../sql-reference/statements/create/quota.md)
-   [ALTER QUOTA](../sql-reference/statements/alter/quota.md#alter-quota-statement)
-   [DROP QUOTA](../sql-reference/statements/drop.md#drop-quota-statement)
-   [SHOW CREATE QUOTA](../sql-reference/statements/show.md#show-create-quota-statement)
-   [SHOW QUOTA](../sql-reference/statements/show.md#show-quota-statement)
-   [SHOW QUOTAS](../sql-reference/statements/show.md#show-quotas-statement)

## Enabling SQL-driven Access Control and Account Management {#enabling-access-control}

-   Setup a directory for configurations storage.

    ClickHouse stores access entity configurations in the folder set in the [access_control_path](../operations/server-configuration-parameters/settings.md#access_control_path) server configuration parameter.

-   Enable SQL-driven access control and account management for at least one user account.

    By default, SQL-driven access control and account management is disabled for all users. You need to configure at least one user in the `users.xml` configuration file and set the value of the [access_management](../operations/settings/settings-users.md#access_management-user-setting) setting to 1.

[Original article](https://clickhouse.com/docs/en/operations/access_rights/) <!--hide-->