Engineering

ClickHouse vs Databricks 2026: Comparing Real-Time Analytics and Lakehouse Platforms

Engineering Team

ClickHouse and Databricks represent different philosophies in modern data analytics. ClickHouse is a high-performance columnar database optimised for real-time analytical queries, while Databricks provides a unified lakehouse platform combining data engineering, data science, and SQL analytics. This comparison helps you understand when each platform excels and how to choose between them.

Platform Overview

ClickHouse

ClickHouse is an open-source columnar database management system designed for online analytical processing (OLAP). Originally developed at Yandex for web analytics, it processes petabytes of data with sub-second query latency.

Core strengths:

  • Fastest query performance for structured analytical data
  • Real-time data ingestion and querying
  • Exceptional compression (10-20x)
  • Cost-effective at scale
  • Open source with commercial cloud offering

Databricks

Databricks is a unified data analytics platform built on Apache Spark, offering a lakehouse architecture that combines data lake flexibility with data warehouse performance.

Core strengths:

  • Unified platform for data engineering, ML, and analytics
  • Delta Lake for reliable data lakes
  • Collaborative notebooks for data science
  • Strong governance and security features
  • Deep integration with major cloud providers

Architecture Comparison

ClickHouse Architecture

┌─────────────────────────────────────────────┐
│              ClickHouse Cluster             │
├─────────────┬─────────────┬─────────────────┤
│   Shard 1   │   Shard 2   │    Shard N      │
│  ┌───────┐  │  ┌───────┐  │   ┌───────┐     │
│  │Replica│  │  │Replica│  │   │Replica│     │
│  │   1   │  │  │   1   │  │   │   1   │     │
│  └───────┘  │  └───────┘  │   └───────┘     │
│  ┌───────┐  │  ┌───────┐  │   ┌───────┐     │
│  │Replica│  │  │Replica│  │   │Replica│     │
│  │   2   │  │  │   2   │  │   │   2   │     │
│  └───────┘  │  └───────┘  │   └───────┘     │
└─────────────┴─────────────┴─────────────────┘
         │              │              │
         └──────────────┼──────────────┘

              MergeTree Storage
              (Columnar, Compressed)

Key components:

  • Shared-nothing distributed architecture
  • MergeTree table engine with sorted, partitioned storage
  • Distributed query execution across shards
  • ZooKeeper/ClickHouse Keeper for coordination

Databricks Architecture

┌─────────────────────────────────────────────┐
│           Databricks Workspace              │
├─────────────────────────────────────────────┤
│  ┌─────────┐  ┌─────────┐  ┌─────────────┐  │
│  │ Delta   │  │   ML    │  │   SQL       │  │
│  │ Live    │  │ Runtime │  │ Warehouse   │  │
│  │ Tables  │  │         │  │             │  │
│  └────┬────┘  └────┬────┘  └──────┬──────┘  │
│       │            │              │         │
│       └────────────┼──────────────┘         │
│                    │                        │
│           ┌────────▼────────┐               │
│           │   Delta Lake    │               │
│           │  (Parquet + Tx) │               │
│           └────────┬────────┘               │
└────────────────────┼────────────────────────┘

         Cloud Object Storage (S3/ADLS/GCS)

Key components:

  • Unity Catalog for governance
  • Delta Lake for ACID transactions on data lakes
  • Photon engine for accelerated SQL
  • Auto-scaling compute clusters

Performance Comparison

Query Performance

Query TypeClickHouseDatabricks SQL
Simple aggregation (1B rows)0.5-2s5-15s
Complex JOIN2-10s10-60s
Time-series rollup0.1-1s3-10s
Ad-hoc explorationSub-second5-30s
Concurrent queries (100+)ExcellentGood

ClickHouse advantages:

  • Purpose-built for analytical queries
  • Vectorised execution optimised for modern CPUs
  • Data always hot in optimised columnar format
  • Minimal query startup overhead

Databricks advantages:

  • Better for extremely large joins across tables
  • Handles semi-structured data (JSON, nested) natively
  • Photon engine narrows the gap for SQL workloads
  • Better for complex transformations

Data Ingestion

AspectClickHouseDatabricks
Real-time streamingNative (Kafka, etc.)Structured Streaming
Batch loadingVery fastFast
Latency to queryMillisecondsSeconds to minutes
Data formatsOwn format, ParquetDelta, Parquet, JSON, etc.

Feature Comparison

FeatureClickHouseDatabricks
Query languageSQL (extended)SQL, Python, Scala, R
Real-time analyticsExcellentGood
Machine learningLimitedExcellent (MLflow)
Data engineeringBasicExcellent (Spark)
Data governanceBasicUnity Catalog
NotebooksNoYes
Version controlNoDelta Lake time travel
Semi-structured dataJSON columnsNative nested types
StreamingKafka integrationStructured Streaming

Cost Comparison

ClickHouse (Self-Managed)

Infrastructure costs only:
- Compute: $0.05-0.15 per GB processed
- Storage: $0.02-0.03 per GB/month (compressed)
- No licensing fees (open source)

ClickHouse Cloud

- Compute: $0.30-0.50 per compute hour
- Storage: $0.04 per GB/month
- Data transfer: Standard cloud rates

Databricks

- DBU pricing: $0.07-0.55 per DBU
- Plus underlying cloud compute costs
- SQL Warehouse: $0.22-0.55 per DBU
- Typical total: $0.40-1.00+ per compute hour

Cost analysis:

  • ClickHouse is typically 3-5x cheaper for pure analytical workloads
  • Databricks provides more value when using ML and data engineering features
  • ClickHouse self-managed offers lowest costs with operational overhead

For cost optimisation strategies, see our AWS cloud cost optimisation guide.

Use Case Recommendations

Choose ClickHouse When:

  • Real-time dashboards - Sub-second queries on billions of rows
  • Log and event analytics - High-volume ingestion with instant queries
  • Time-series workloads - Metrics, monitoring, IoT data
  • Cost-sensitive analytics - Maximum performance per dollar
  • High concurrency - Hundreds of concurrent dashboard users

Example: Marketing analytics platform

-- Real-time campaign performance
SELECT
    campaign_id,
    count() AS impressions,
    countIf(clicked) AS clicks,
    countIf(converted) AS conversions,
    sum(revenue) AS total_revenue
FROM ad_events
WHERE event_date >= today() - 7
GROUP BY campaign_id
ORDER BY total_revenue DESC
LIMIT 100

Choose Databricks When:

  • Unified data platform - Engineering, science, and analytics together
  • Machine learning workflows - Training, deployment, monitoring
  • Complex ETL pipelines - Multi-step transformations
  • Data lake modernisation - Adding reliability to existing lakes
  • Collaborative analysis - Notebooks for team exploration

Example: ML feature pipeline

# Delta Live Tables pipeline
@dlt.table
def customer_features():
    return (
        dlt.read("raw_transactions")
        .groupBy("customer_id")
        .agg(
            F.count("*").alias("transaction_count"),
            F.sum("amount").alias("total_spend"),
            F.avg("amount").alias("avg_transaction")
        )
    )

Hybrid Architecture

Many organisations use both platforms:

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   Sources   │────▶│  Databricks │────▶│  ClickHouse │
│  (Raw Data) │     │   (ETL/ML)  │     │ (Dashboards)│
└─────────────┘     └─────────────┘     └─────────────┘


                    ┌─────────────┐
                    │   ML Models │
                    │  (Serving)  │
                    └─────────────┘
  • Databricks handles data engineering and ML
  • ClickHouse serves real-time dashboards
  • Best of both worlds for comprehensive analytics

Integration Considerations

ClickHouse Integrations

  • Ingestion: Kafka, Kinesis, RabbitMQ, HTTP
  • BI Tools: Grafana, Metabase, Superset, Tableau
  • Orchestration: Airflow, Dagster, Prefect
  • CDC: Debezium, Maxwell, custom

Databricks Integrations

  • Cloud native: Deep AWS, Azure, GCP integration
  • Data sources: 100+ connectors
  • ML tools: MLflow, TensorFlow, PyTorch
  • BI Tools: Native SQL interface, Power BI, Tableau
  • Governance: Unity Catalog, external metastores

Both platforms integrate with modern observability platforms for monitoring query performance.

Operational Comparison

ClickHouse Operations

Pros:

  • Simple to operate once configured
  • Predictable performance
  • Low resource overhead

Cons:

  • Requires understanding of data modelling
  • Schema changes need planning
  • Self-managed requires expertise

Databricks Operations

Pros:

  • Fully managed infrastructure
  • Auto-scaling compute
  • Integrated monitoring

Cons:

  • Can be complex to optimise costs
  • Cluster startup latency
  • Requires Spark expertise for advanced use

Migration Considerations

From Databricks to ClickHouse

Consider when:

  • Queries are primarily analytical aggregations
  • Real-time requirements exceed Databricks capabilities
  • Cost optimisation is critical

From ClickHouse to Databricks

Consider when:

  • Adding ML capabilities to analytics
  • Need for complex data transformations
  • Unified platform benefits outweigh performance trade-offs

Conclusion

ClickHouse and Databricks serve different primary purposes:

ClickHouse excels at real-time analytical queries with unmatched performance and cost efficiency. Choose it for dashboards, monitoring, and high-concurrency analytical workloads.

Databricks provides a unified platform for data engineering, data science, and SQL analytics. Choose it when you need ML capabilities, complex transformations, and collaborative data work.

Many organisations benefit from using both: Databricks for data engineering and ML, ClickHouse for real-time analytics and dashboards.

Need help building your analytics architecture? Contact our data engineering team to discuss your requirements.

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