How to Self-Host ClickHouse in PostgreSQL

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How do I self-host ClickHouse and connect it to PostgreSQL?

Deploy ClickHouse on your own infrastructure, then connect it to PostgreSQL for lightning-fast analytics.

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Description

Example H2

Example H3

Why self-host ClickHouse instead of using ClickHouse Cloud?

Self-hosting gives full control over hardware, security, and cost. You can fine-tune storage, keep data on-prem, and avoid recurring SaaS fees. Teams with strict compliance or large data volumes benefit most.

What hardware and OS does ClickHouse need?

ClickHouse runs on any modern 64-bit Linux. Prefer SSDs, 32+ GB RAM, and multiple CPU cores. Use RAID-10 for redundancy.Network-attached storage can throttle performance, so keep data on local disks when possible.

How do I install ClickHouse with Docker Compose?

Minimal docker-compose.yml

version: "3.9" services: clickhouse: image: clickhouse/clickhouse-server:latest container_name: ch_server ports: - "9000:9000" # native client - "8123:8123" # HTTP interface ulimits: nofile: soft: 262144 hard: 262144 volumes: - ./ch_data:/var/lib/clickhouse

Start the cluster

docker compose up -d

Verify with docker logs -f ch_server.The server is ready when you see “Ready for connections.”

How do I create e-commerce tables in ClickHouse?

Customers

CREATE TABLE Customers ( id UInt32, name String, email String, created_at DateTime ) ENGINE = MergeTree() ORDER BY id;

Orders

CREATE TABLE Orders ( id UInt32, customer_id UInt32, order_date Date, total_amount Decimal(10,2) ) ENGINE = MergeTree() ORDER BY (customer_id, order_date);

How do I load data from PostgreSQL to ClickHouse?

Use clickhouse-client with --query piping:

PGPASSWORD=$PG_PASS psql -h pg_host -U pg_user -d shop -c \ "COPY (SELECT * FROM Customers) TO STDOUT" | \ clickhouse-client --query="INSERT INTO Customers FORMAT CSV" --format_csv_delimiter=','

Repeat for each table or automate with clickhouse-cloud-export or Airbyte.

How do I run analytical queries?

SELECT p.name AS product, sum(oi.quantity) AS units_sold, sum(oi.quantity * p.price) AS revenue FROM OrderItems oi JOIN Products p ON p.id = oi.product_id GROUP BY product ORDER BY revenue DESC LIMIT 10;

This query scans billions of rows in milliseconds thanks to ClickHouse’s columnar engine.

Best practices for production deployments?

Enable replicated tables for HA, schedule OPTIMIZE TABLE, monitor disk I/O, and keep merges under control with proper PARTITION BY.Encrypt traffic with TLS and restrict ports in your firewall.

What are common mistakes to avoid?

Skipping ORDER BY leads to slow reads. Over-partitioning inflates metadata and increases merges. See details below.

Why How to Self-Host ClickHouse in PostgreSQL is important

How to Self-Host ClickHouse in PostgreSQL Example Usage


-- Top 5 customers by lifetime value
SELECT c.id, c.name, sum(o.total_amount) AS lifetime_value
FROM Customers c
JOIN Orders o ON o.customer_id = c.id
GROUP BY c.id, c.name
ORDER BY lifetime_value DESC
LIMIT 5;

How to Self-Host ClickHouse in PostgreSQL Syntax


-- Create a MergeTree table
CREATE TABLE Customers (
  id UInt32,
  name String,
  email String,
  created_at DateTime
) ENGINE = MergeTree()
ORDER BY id;

-- Insert data directly
INSERT INTO Customers (id, name, email, created_at) VALUES
(1, 'Ada Lovelace', 'ada@example.com', now());

-- Query with conditions
SELECT * FROM Customers WHERE id = 1;

-- Join tables for aggregated sales
SELECT c.name, sum(o.total_amount) AS lifetime_value
FROM Customers c
JOIN Orders o ON o.customer_id = c.id
GROUP BY c.name;

Common Mistakes

Forgetting the ORDER BY key. MergeTree tables without an ORDER BY read entire partitions, killing performance. Always define a key matching your most common filter or join columns.
Using one huge partition. A single partition makes merges heavy and hinders parallelism. Partition by month or day to balance insert speed and query efficiency.