> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-parallel-read-in-order-multi-part.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# ClickHouse dictionary source

> Configure a ClickHouse table as a dictionary source.

Example of settings:

<Tabs>
  <Tab title="DDL">
    ```sql theme={null}
    SOURCE(CLICKHOUSE(
        host 'example01-01-1'
        port 9000
        user 'dict_reader'
        password 'dict_reader_password'
        db 'default'
        table 'ids'
        where 'id=10'
        secure 1
        query 'SELECT id, value_1, value_2 FROM default.ids'
    ));
    ```
  </Tab>

  <Tab title="Configuration file">
    ```xml theme={null}
    <source>
        <clickhouse>
            <host>example01-01-1</host>
            <port>9000</port>
            <user>dict_reader</user>
            <password>dict_reader_password</password>
            <db>default</db>
            <table>ids</table>
            <where>id=10</where>
            <secure>1</secure>
            <query>SELECT id, value_1, value_2 FROM default.ids</query>
        </clickhouse>
    </source>
    ```
  </Tab>
</Tabs>

<br />

Setting fields:

| Setting | Description |
| - | - |
| `host` | The ClickHouse host. If it is a local host, the query is processed without any network activity. To improve fault tolerance, you can create a [Distributed](/reference/engines/table-engines/special/distributed) table and enter it in subsequent configurations. |
| `port` | The port on the ClickHouse server. |
| `user` | Name of the ClickHouse user. |
| `password` | Password of the ClickHouse user. |
| `db` | Name of the database. |
| `table` | Name of the table. |
| `where` | The selection criteria. Optional. |
| `invalidate_query` | Query for checking the dictionary status. Optional. Read more in the section [Refreshing dictionary data using LIFETIME](/reference/statements/create/dictionary/lifetime). |
| `secure` | Use SSL for connection. |
| `query` | The custom query. Optional. |

<Note>
  The `table` or `where` fields cannot be used together with the `query` field. And either one of the `table` or `query` fields must be declared.
</Note>

<Note>
  In ClickHouse Cloud, when a user other than `default` creates the dictionary, the source must specify both `user` and `password`, and `user` cannot be `default`. Otherwise `CREATE DICTIONARY` fails with a `BAD_ARGUMENTS` error. Use a dedicated user that has `SELECT` on the source table.
</Note>