mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-19 21:03:51 +00:00
60 lines
2.1 KiB
Markdown
60 lines
2.1 KiB
Markdown
---
|
||
toc_priority: 58
|
||
toc_title: Permissions for Queries
|
||
---
|
||
|
||
# Permissions for Queries {#permissions_for_queries}
|
||
|
||
Queries in ClickHouse can be divided into several types:
|
||
|
||
1. Read data queries: `SELECT`, `SHOW`, `DESCRIBE`, `EXISTS`.
|
||
2. Write data queries: `INSERT`, `OPTIMIZE`.
|
||
3. Change settings query: `SET`, `USE`.
|
||
4. [DDL](https://en.wikipedia.org/wiki/Data_definition_language) queries: `CREATE`, `ALTER`, `RENAME`, `ATTACH`, `DETACH`, `DROP` `TRUNCATE`.
|
||
5. `KILL QUERY`.
|
||
|
||
The following settings regulate user permissions by the type of query:
|
||
|
||
- [readonly](#settings_readonly) — Restricts permissions for all types of queries except DDL queries.
|
||
- [allow_ddl](#settings_allow_ddl) — Restricts permissions for DDL queries.
|
||
|
||
`KILL QUERY` can be performed with any settings.
|
||
|
||
## readonly {#settings_readonly}
|
||
|
||
Restricts permissions for reading data, write data and change settings queries.
|
||
|
||
See how the queries are divided into types [above](#permissions_for_queries).
|
||
|
||
Possible values:
|
||
|
||
- 0 — All queries are allowed.
|
||
- 1 — Only read data queries are allowed.
|
||
- 2 — Read data and change settings queries are allowed.
|
||
|
||
After setting `readonly = 1`, the user can’t change `readonly` and `allow_ddl` settings in the current session.
|
||
|
||
When using the `GET` method in the [HTTP interface](../../interfaces/http.md), `readonly = 1` is set automatically. To modify data, use the `POST` method.
|
||
|
||
Setting `readonly = 1` prohibit the user from changing all the settings. There is a way to prohibit the user
|
||
from changing only specific settings, for details see [constraints on settings](../../operations/settings/constraints-on-settings.md).
|
||
|
||
Default value: 0
|
||
|
||
## allow_ddl {#settings_allow_ddl}
|
||
|
||
Allows or denies [DDL](https://en.wikipedia.org/wiki/Data_definition_language) queries.
|
||
|
||
See how the queries are divided into types [above](#permissions_for_queries).
|
||
|
||
Possible values:
|
||
|
||
- 0 — DDL queries are not allowed.
|
||
- 1 — DDL queries are allowed.
|
||
|
||
You can’t execute `SET allow_ddl = 1` if `allow_ddl = 0` for the current session.
|
||
|
||
Default value: 1
|
||
|
||
[Original article](https://clickhouse.com/docs/en/operations/settings/permissions_for_queries/) <!--hide-->
|