Nessie catalog

In this guide, we will walk you through the steps to query your data using ClickHouse and the Nessie Catalog.

Integration with the Nessie 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 Nessie catalog.

Nessie is an open-source transactional catalog for data lakes that provides:

• Git-inspired data version control with branches and commits
• Cross-table transactions and visibility guarantees
• REST API compliance with the Iceberg REST catalog specification
• Open data lake approach supporting Hive, Spark, Dremio, Trino, and more
• Production-ready deployment on Docker or Kubernetes

As this feature is experimental, you will need to enable it using: SET allow_experimental_database_iceberg = 1;

Local Development Setup

For local development and testing, you can use a containerized Nessie setup. This approach is ideal for learning, prototyping, and development environments.

Prerequisites

1. Docker and Docker Compose: Ensure Docker is installed and running
2. Sample Setup: You can use the official Nessie docker-compose setup

Setting up Local Nessie Catalog

You can use the official Nessie docker-compose setup which provides a complete environment with Nessie, in-memory version store, and MinIO for object storage.

Step 1: Create a new folder in which to run the example, then create a file docker-compose.yml with the following configuration:

version: '3.8'

services:
  nessie:
    image: ghcr.io/projectnessie/nessie:latest
    ports:
      - "19120:19120"
    environment:
      - nessie.version.store.type=IN_MEMORY
      - nessie.catalog.default-warehouse=warehouse
      - nessie.catalog.warehouses.warehouse.location=s3://my-bucket/
      - nessie.catalog.service.s3.default-options.endpoint=http://minio:9000/
      - nessie.catalog.service.s3.default-options.access-key=urn:nessie-secret:quarkus:nessie.catalog.secrets.access-key
      - nessie.catalog.service.s3.default-options.path-style-access=true
      - nessie.catalog.service.s3.default-options.auth-type=STATIC
      - nessie.catalog.secrets.access-key.name=admin
      - nessie.catalog.secrets.access-key.secret=password
      - nessie.catalog.service.s3.default-options.region=us-east-1
      - nessie.server.authentication.enabled=false
    depends_on:
      minio:
        condition: service_healthy
    networks:
      - iceberg_net

  minio:
    image: quay.io/minio/minio
    ports:
      - "9002:9000"
      - "9003:9001"
    environment:
      - MINIO_ROOT_USER=admin
      - MINIO_ROOT_PASSWORD=password
      - MINIO_REGION=us-east-1
    healthcheck:
      test: ["CMD", "mc", "ready", "local"]
      interval: 5s
      timeout: 10s
      retries: 5
      start_period: 30s
    entrypoint: >
      /bin/sh -c "
      minio server /data --console-address ':9001' &
      sleep 10;
      mc alias set myminio http://localhost:9000 admin password;
      mc mb myminio/my-bucket --ignore-existing;
      tail -f /dev/null"
    networks:
      - iceberg_net

  clickhouse:
    image: clickhouse/clickhouse-server:head
    container_name: nessie-clickhouse
    user: '0:0'  # Ensures root permissions
    ports:
      - "8123:8123"
      - "9000:9000"
    volumes:
      - clickhouse_data:/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=
    depends_on:
      nessie:
        condition: service_started
      minio:
        condition: service_healthy

volumes:
  clickhouse_data:

networks:
  iceberg_net:
    driver: bridge

Step 2: Run the following command to start the services:

docker compose up -d

Step 3: Wait for all services to be ready. You can check the logs:

docker-compose logs -f

The Nessie setup uses an in-memory version store and requires that sample data be loaded into the Iceberg tables first. Make sure the environment has created and populated the tables before attempting to query them through ClickHouse.

Connecting to Local Nessie Catalog

Connect to your ClickHouse container:

docker exec -it nessie-clickhouse clickhouse-client

Then create the database connection to the Nessie catalog:

SET allow_experimental_database_iceberg = 1;

CREATE DATABASE demo
ENGINE = DataLakeCatalog('http://nessie:19120/iceberg', 'admin', 'password')
SETTINGS catalog_type = 'rest', storage_endpoint = 'http://minio:9002/my-bucket', warehouse = 'warehouse'

Querying Nessie catalog tables using ClickHouse

Now that the connection is in place, you can start querying via the Nessie catalog. For example:

USE demo;

SHOW TABLES;

If your setup includes sample data (such as the taxi dataset), you should see tables like:

┌─name──────────┐
│ default.taxis │
└───────────────┘

If you don’t see any tables, this usually means:

1. The environment hasn’t created the sample tables yet
2. The Nessie catalog service isn’t fully initialized
3. The sample data loading process hasn’t completed

You can check the Nessie logs to see the catalog activity:

docker-compose logs nessie

To query a table (if available):

SELECT count(*) FROM `default.taxis`;

┌─count()─┐
│ 2171187 │
└─────────┘

Backticks required

Backticks are required because ClickHouse doesn’t support more than one namespace.

To inspect the table DDL:

SHOW CREATE TABLE `default.taxis`;

┌─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://localhost:9002/my-bucket/default/taxis/', 'admin', '[HIDDEN]')      │
└───────────────────────────────────────────────────────────────────────────────────────────────┘

Loading data from your Data Lake into ClickHouse

If you need to load data from the Nessie catalog into ClickHouse, start by creating a local ClickHouse table:

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 Nessie catalog table via an INSERT INTO SELECT:

INSERT INTO taxis 
SELECT * FROM demo.`default.taxis`;