add(clickhouse): credentials integration (#4)

docs/products/clickhouse/concepts/data-integration-overview.md

@@ -0,0 +1,114 @@
+---
+title: Aiven for ClickHouse® data service integration
+sidebar_label: Data integration
+keywords: [data service integration, data source integration, managed credentials integration, managed databases integration, named collections]
+---
+
+import {ConsoleIcon} from "@site/src/components/ConsoleIcons";
+
+Aiven for ClickHouse® supports different types of integration allowing you to efficiently connect with other services or data sources and access the data to be processed.
+
+There are a few ways of classifying integration types supported in Aiven for ClickHouse:
+
+- [By purpose](/docs/products/clickhouse/concepts/data-integration-overview#observability-integrations-vs-data-source-integrations):
+  observability integration vs data source integration
+- [By location](/docs/products/clickhouse/concepts/data-integration-overview#integrations-between-aiven-managed-services-vs-external-integrations):
+  integration between Aiven-managed services vs external integration (between an
+  Aiven-managed service and an external service)
+- By scope: [managed databases integration](/docs/products/clickhouse/concepts/data-integration-overview#managed-databases-integration) and
+  [managed credentials integration](/docs/products/clickhouse/concepts/data-integration-overview#managed-credentials-integration)
+
+## Observability integrations vs data source integrations
+
+Aiven for ClickHouse supports observability integrations and data source integrations,
+which have different purposes:
+
+- [Observability integration](/docs/products/clickhouse/howto/list-integrations) is
+  connecting to other services (either Aiven-managed or external ones) to expose and
+  process logs and metrics.
+- Data service integration is connecting to other services (either Aiven-managed or external)
+  to use them as data sources. In Aiven for ClickHouse, data service integration is
+  possible with the following data source types:
+
+  - Apache Kafka®
+  - PostgreSQL®
+  - MySQL®
+  - ClickHouse®
+  - Amazon S3®
+
+## Integrations between Aiven-managed services vs external integrations
+
+By enabling data service integrations, you create streaming data pipelines across
+services. Depending on where the services are located, you can have either
+integrations between Aiven-managed services or external integrations (between an Aiven service
+and an external data source or application).
+
+For integrating with external data sources, Aiven for ClickHouse provides two types of
+data service integrations:
+
+- [Managed databases](/docs/products/clickhouse/concepts/data-integration-overview#managed-databases-integration)
+- [Managed credentials](/docs/products/clickhouse/concepts/data-integration-overview#managed-credentials-integration)
+
+## Managed credentials integration
+
+The managed credentials integration uses the
+[ClickHouse named collections](https://clickhouse.com/docs/en/operations/named-collections)
+logic. It allows storing key-value pairs that are to be used as credentials when
+connecting to external data sources. To integrate data, you create tables using table
+engines. With the managed credentials integration enabled,
+querying the data is easier and quicker since you no longer need connections parameters in
+each query. They are stored and available from credential storage in Aiven.
+
+Managed credentials integration in Aiven for ClickHouse is supported with the following
+data source types:
+
+- PostgreSQL®
+- MySQL®
+- ClickHouse®
+- Amazon S3®
+
+:::important
+The managed credentials integration works one-way: It allows to integrate with data source
+and access your data from Aiven for ClickHouse, but it doesn’t allow to access Aiven for
+ClickHouse data from the integrated data source.
+:::
+
+For information on how table engines work in Aiven for ClickHouse services, preview
+[Engines: database and table](/docs/products/clickhouse/concepts/service-architecture#engines-database-and-table).
+For the list of table engines available in Aiven for ClickHouse, check
+[Supported table engines](/docs/products/clickhouse/reference/supported-table-engines).
+
+## Managed databases integration
+
+The managed databases integration allows using a database engine for handling your
+external data. When enabled, this type of integration provides you with an automatically
+created database, where the remote data is exposed.
+
+Managed databases integration in Aiven for ClickHouse is supported with the following
+data source types:
+
+- PostgreSQL®
+- Apache Kafka®
+
+For information on how database engines work in Aiven for ClickHouse services, preview
+[Engines: database and table](/docs/products/clickhouse/concepts/service-architecture#engines-database-and-table).
+For more information on ClickHouse database engines, see
+[Database engines](https://clickhouse.com/docs/en/engines/database-engines).
+
+## Supported data source types
+
+Depending on a data source type, Aiven for ClickHouse supports different integration modes.
+
+| Data source type | Data source integration<br/>(with Aiven service <br/>or external source)| Managed databases integration| Managed credentials integration |
+|------------------|----------------------------|------------------------------|---------------------------------|
+| PostgreSQL       | <ConsoleIcon name="tick"/> | <ConsoleIcon name="tick"/>   | <ConsoleIcon name="tick"/>      |
+| MySQL            | <ConsoleIcon name="tick"/> | <ConsoleIcon name="cross"/>  | <ConsoleIcon name="tick"/>      |
+| Apache Kafka     | <ConsoleIcon name="tick"/> | <ConsoleIcon name="tick"/>   | <ConsoleIcon name="cross"/>     |
+| ClickHouse       | <ConsoleIcon name="tick"/> | <ConsoleIcon name="cross"/>  | <ConsoleIcon name="tick"/>     |
+| Amazon S3        | <ConsoleIcon name="tick"/> | <ConsoleIcon name="cross"/>  | <ConsoleIcon name="tick"/>      |
+
+## Related pages
+
+- [Set up Aiven for ClickHouse® data service integration](/docs/products/clickhouse/howto/data-service-integration)
+- [Manage Aiven for ClickHouse® integration databases](/docs/products/clickhouse/howto/integration-databases)
+- [Integrate your Aiven for ClickHouse® service](/docs/products/clickhouse/howto/list-integrations)

docs/products/clickhouse/howto/copy-data-across-instances.md

@@ -15,16 +15,28 @@ Details of the source (remote) server
 
 ## Copy data
 
-1.  From your target servers, use the `remoteSecure()`
+1.  From your target server, use the `remoteSecure()`
     function to select data from the source server.
 
-    ```shell
+    ```sql
     SELECT * FROM remoteSecure('HOSTNAME:PORT', db.remote_engine_table, 'USERNAME', 'PASSWORD') LIMIT 3;
     ```
 
+    :::tip
+    If you have the
+    [managed credentials integration](/docs/products/clickhouse/concepts/data-integration-overview#managed-credentials-integration)
+    enabled, you can use instead:
+
+    ```sql
+    SELECT * FROM remoteSecure('service_YOUR_REMOTE_CLUSTER', db.remote_engine_table) LIMIT 3;
+    ```
+
+    See how to [enable the managed credentials integration](/docs/products/clickhouse/howto/data-service-integration#integrate-with-external-data-sources).
+    :::
+
 1.  Insert the selected data into the target server.
 
-    ```shell
+    ```sql
     INSERT INTO [db.]table [(c1, c2, c3)] SELECT ...
     ```