Add REST catalog support in docs (#1)

docs/integrations/index.mdx

@@ -244,6 +244,7 @@ We are actively compiling this list of ClickHouse integrations below, so it's no
 |RabbitMQ|<Rabbitmqsvg alt="RabbitMQ logo" style={{width: '3rem', 'height': '3rem'}}/>|Data ingestion|Allows ClickHouse to connect [RabbitMQ](https://www.rabbitmq.com/).|[Documentation](/engines/table-engines/integrations/rabbitmq)|
 |Redis|<Redissvg alt="Redis logo" style={{width: '3rem', 'height': '3rem'}}/>|Data ingestion|Allows ClickHouse to use [Redis](https://redis.io/) as a dictionary source.|[Documentation](/sql-reference/dictionaries/index.md#redis)|
 |Redpanda|<Image img={redpanda} alt="Redpanda logo" size="logo"/>|Data ingestion|Redpanda is the streaming data platform for developers. It's API-compatible with Apache Kafka, but 10x faster, much easier to use, and more cost effective|[Blog](https://redpanda.com/blog/real-time-olap-database-clickhouse-redpanda)|
+|REST Catalog||Data ingestion|Integration with REST Catalog specification for Iceberg tables, supporting multiple catalog providers including Tabular.io.|[Documentation](/use-cases/data-lake/rest-catalog)|
 |Rust|<Image img={rust} size="logo" alt="Rust logo"/>|Language client|A typed client for ClickHouse|[Documentation](/integrations/language-clients/rust.md)|
 |SQLite|<Sqlitesvg alt="Sqlite logo" style={{width: '3rem', 'height': '3rem'}}/>|Data ingestion|Allows to import and export data to SQLite and supports queries to SQLite tables directly from ClickHouse.|[Documentation](/engines/table-engines/integrations/sqlite)|
 |Superset|<Supersetsvg alt="Superset logo" style={{width: '3rem'}}/>|Data visualization|Explore and visualize your ClickHouse data with Apache Superset.|[Documentation](/integrations/data-visualization/superset-and-clickhouse.md)|

docs/use-cases/data_lake/index.md

@@ -4,12 +4,13 @@ pagination_prev: null
 pagination_next: null
 slug: /use-cases/data-lake
 title: 'Data Lake'
-keywords: ['data lake', 'glue', 'unity']
+keywords: ['data lake', 'glue', 'unity', 'rest']
 ---
 
-ClickHouse supports integration with multiple catalogs (Unity, Glue, Polaris, etc.).
+ClickHouse supports integration with multiple catalogs (Unity, Glue, REST, Polaris, etc.).
 
 | Page | Description |
 |-----|-----|
 | [Querying data in S3 using ClickHouse and the Glue Data Catalog](/use-cases/data-lake/glue-catalog) |  Query your data in S3 buckets using ClickHouse and the Glue Data Catalog. |
 | [Querying data in S3 using ClickHouse and the Unity Data Catalog](/use-cases/data-lake/unity-catalog) | Query your using the Unity Catalog. |
+| [Querying data in S3 using ClickHouse and the REST Catalog](/use-cases/data-lake/rest-catalog) | Query your data using the REST Catalog (Tabular.io). |

docs/use-cases/data_lake/rest_catalog.md

@@ -0,0 +1,193 @@
+---
+slug: /use-cases/data-lake/rest-catalog
+sidebar_label: 'REST Catalog'
+title: 'REST Catalog'
+pagination_prev: null
+pagination_next: null
+description: 'In this guide, we will walk you through the steps to query
+ your data in S3 buckets using ClickHouse and the REST Catalog.'
+keywords: ['REST', 'Tabular', 'Data Lake', 'Iceberg']
+show_related_blogs: true
+---
+
+import ExperimentalBadge from '@theme/badges/ExperimentalBadge';
+
+<ExperimentalBadge/>
+
+:::note
+Integration with the REST Catalog works with Iceberg tables only.
+This integration supports both AWS S3 and other cloud storage providers.
+:::
+
+ClickHouse supports integration with multiple catalogs (Unity, Glue, REST, Polaris, etc.). This guide will walk you through the steps to query your data using ClickHouse and the [REST Catalog](https://github.com/apache/iceberg/blob/main/open-api/rest-catalog-open-api.yaml/) specification.
+
+The REST Catalog is a standardized API specification for Iceberg catalogs, supported by various platforms including:
+- **Local development environments** (using docker-compose setups)
+- **Managed services** like Tabular.io
+- **Self-hosted** REST catalog implementations
+
+:::note
+As this feature is experimental, you will need to enable it using:
+`SET allow_experimental_database_rest_catalog = 1;`
+:::
+
+## Local Development Setup {#local-development-setup}
+
+For local development and testing, you can use a containerized REST catalog setup. This approach is ideal for learning, prototyping, and development environments.
+
+### Prerequisites {#local-prerequisites}
+
+1. **Docker and Docker Compose**: Ensure Docker is installed and running
+2. **Sample Setup**: You can use various docker-compose setups (see Alternative Docker Images below)
+
+### Setting up Local REST Catalog {#setting-up-local-rest-catalog}
+
+You can use various containerized REST catalog implementations such as **[Databricks docker-spark-iceberg](https://github.com/databricks/docker-spark-iceberg/blob/main/docker-compose.yml?ref=blog.min.io)** which provides a complete Spark + Iceberg + REST catalog environment with docker-compose, making it ideal for testing Iceberg integrations.
+
+You'll need to add ClickHouse as a dependency in your docker-compose setup:
+
+```yaml
+clickhouse:
+  image: clickhouse/clickhouse-server:main
+  container_name: clickhouse
+  user: '0:0'  # Ensures root permissions
+  networks:
+    iceberg_net:
+  ports:
+    - "8123:8123"
+    - "9002:9000"
+  volumes:
+    - ./clickhouse:/var/lib/clickhouse
+    - ./clickhouse/data_import:/var/lib/clickhouse/data_import  # Mount dataset folder
+  networks:
+    - iceberg_net
+  environment:
+    - CLICKHOUSE_DB=default
+    - CLICKHOUSE_USER=default
+    - CLICKHOUSE_DO_NOT_CHOWN=1
+    - CLICKHOUSE_PASSWORD=
+```
+
+### Connecting to Local REST Catalog {#connecting-to-local-rest-catalog}
+
+Connect to your ClickHouse container:
+
+```bash
+docker exec -it clickhouse clickhouse-client
+```
+
+Then create the database connection to the REST catalog:
+
+```sql
+CREATE DATABASE demo
+ENGINE = DataLakeCatalog('http://rest:8181/v1', 'admin', 'password')
+SETTINGS 
+    catalog_type = 'rest', 
+    storage_endpoint = 'http://minio:9000/lakehouse', 
+    warehouse = 'demo'
+```
+
+## Querying REST catalog tables using ClickHouse {#querying-rest-catalog-tables-using-clickhouse}
+
+Now that the connection is in place, you can start querying via the REST catalog. For example:
+
+```sql
+USE demo;
+
+SHOW TABLES;
+```
+
+```sql title="Response"
+┌─name──────────┐
+│ default.taxis │
+└───────────────┘
+```
+
+To query a table:
+
+```sql
+SELECT count(*) FROM `default.taxis`;
+```
+
+```sql title="Response"
+┌─count()─┐
+│ 2171187 │
+└─────────┘
+```
+
+:::note Backticks required
+Backticks are required because ClickHouse doesn't support more than one namespace.
+:::
+
+To inspect the table DDL:
+
+```sql
+SHOW CREATE TABLE `default.taxis`;
+```
+
+```sql title="Response"
+┌─statement─────────────────────────────────────────────────────────────────────────────────────┐
+│ CREATE TABLE demo.`default.taxis`                                                             │
+│ (                                                                                             │
+│     `VendorID` Nullable(Int64),                                                               │
+│     `tpep_pickup_datetime` Nullable(DateTime64(6)),                                           │
+│     `tpep_dropoff_datetime` Nullable(DateTime64(6)),                                          │
+│     `passenger_count` Nullable(Float64),                                                      │
+│     `trip_distance` Nullable(Float64),                                                        │
+│     `RatecodeID` Nullable(Float64),                                                           │
+│     `store_and_fwd_flag` Nullable(String),                                                    │
+│     `PULocationID` Nullable(Int64),                                                           │
+│     `DOLocationID` Nullable(Int64),                                                           │
+│     `payment_type` Nullable(Int64),                                                           │
+│     `fare_amount` Nullable(Float64),                                                          │
+│     `extra` Nullable(Float64),                                                                │
+│     `mta_tax` Nullable(Float64),                                                              │
+│     `tip_amount` Nullable(Float64),                                                           │
+│     `tolls_amount` Nullable(Float64),                                                         │
+│     `improvement_surcharge` Nullable(Float64),                                                │
+│     `total_amount` Nullable(Float64),                                                         │
+│     `congestion_surcharge` Nullable(Float64),                                                 │
+│     `airport_fee` Nullable(Float64)                                                           │
+│ )                                                                                             │
+│ ENGINE = Iceberg('http://minio:9000/lakehouse/warehouse/default/taxis/', 'admin', '[HIDDEN]') │
+└───────────────────────────────────────────────────────────────────────────────────────────────┘
+```
+
+## Loading data from your Data Lake into ClickHouse {#loading-data-from-your-data-lake-into-clickhouse}
+
+If you need to load data from the REST catalog into ClickHouse, start by creating a local ClickHouse table:
+
+```sql
+CREATE TABLE taxis
+(
+    `VendorID` Int64,
+    `tpep_pickup_datetime` DateTime64(6),
+    `tpep_dropoff_datetime` DateTime64(6),
+    `passenger_count` Float64,
+    `trip_distance` Float64,
+    `RatecodeID` Float64,
+    `store_and_fwd_flag` String,
+    `PULocationID` Int64,
+    `DOLocationID` Int64,
+    `payment_type` Int64,
+    `fare_amount` Float64,
+    `extra` Float64,
+    `mta_tax` Float64,
+    `tip_amount` Float64,
+    `tolls_amount` Float64,
+    `improvement_surcharge` Float64,
+    `total_amount` Float64,
+    `congestion_surcharge` Float64,
+    `airport_fee` Float64
+)
+ENGINE = MergeTree()
+PARTITION BY toYYYYMM(tpep_pickup_datetime)
+ORDER BY (VendorID, tpep_pickup_datetime, PULocationID, DOLocationID);
+```
+
+Then load the data from your REST catalog table via an `INSERT INTO SELECT`:
+
+```sql
+INSERT INTO taxis 
+SELECT * FROM demo.`default.taxis`;
+```

sidebars.js

@@ -167,7 +167,8 @@ const sidebars = {
           link: { type: "doc", id: "use-cases/data_lake/index" },
           items: [
             "use-cases/data_lake/glue_catalog",
-            "use-cases/data_lake/unity_catalog" 
+            "use-cases/data_lake/unity_catalog",
+            "use-cases/data_lake/rest_catalog"
           ]
         }
       ]