Engineering

ClickHouse vs TimescaleDB 2026: Time-Series Database Comparison

Engineering Team

ClickHouse and TimescaleDB are both excellent choices for time-series data, but with different architectural foundations. TimescaleDB extends PostgreSQL with time-series optimisations, while ClickHouse is purpose-built for analytical workloads. This comparison helps you choose the right database for your time-series requirements.

Platform Overview

ClickHouse

ClickHouse is a columnar analytical database designed for fast aggregations on large datasets, with excellent performance for time-series workloads.

Time-series strengths:

  • Blazing fast aggregations
  • Exceptional compression
  • Real-time ingestion
  • Horizontal scaling
  • Native time-series functions

TimescaleDB

TimescaleDB is a PostgreSQL extension that adds time-series capabilities while maintaining full PostgreSQL compatibility.

Time-series strengths:

  • Full PostgreSQL compatibility
  • Automatic partitioning (hypertables)
  • Continuous aggregates
  • Native compression
  • Familiar SQL ecosystem

Architecture Comparison

ClickHouse Time-Series Architecture

-- Optimised time-series table
CREATE TABLE metrics (
    timestamp DateTime64(3),
    metric_name LowCardinality(String),
    tags Map(LowCardinality(String), String),
    value Float64
) ENGINE = MergeTree()
PARTITION BY toYYYYMM(timestamp)
ORDER BY (metric_name, timestamp)
TTL timestamp + INTERVAL 90 DAY

Key features:

  • Columnar storage for efficient scans
  • Partitioning by time periods
  • Sorted data for range queries
  • Automatic TTL-based deletion

TimescaleDB Time-Series Architecture

-- Hypertable for time-series
CREATE TABLE metrics (
    timestamp TIMESTAMPTZ NOT NULL,
    metric_name TEXT NOT NULL,
    tags JSONB,
    value DOUBLE PRECISION
);

SELECT create_hypertable('metrics', 'timestamp');

-- Add compression
ALTER TABLE metrics SET (
    timescaledb.compress,
    timescaledb.compress_segmentby = 'metric_name'
);

Key features:

  • Automatic time-based partitioning
  • Transparent chunk management
  • Native PostgreSQL compatibility
  • Built-in compression policies

Performance Comparison

Query Performance

Query TypeClickHouseTimescaleDB
Simple aggregation (1B rows)0.5s3-5s
Time-bucket aggregation0.3s1-2s
Downsampling query0.8s2-4s
Last value per series0.2s0.5-1s
High-cardinality GROUP BY1s5-10s
Complex JOIN2s1-2s

ClickHouse advantages:

  • 3-10x faster for pure analytical queries
  • Better performance at extreme scale
  • More efficient high-cardinality handling

TimescaleDB advantages:

  • Better JOIN performance (PostgreSQL optimiser)
  • Continuous aggregates reduce query load
  • More efficient for mixed OLTP/OLAP

Ingestion Performance

MetricClickHouseTimescaleDB
Ingestion rate1M+ rows/sec100K-500K rows/sec
Batch insertExcellentGood
Single-row insertGood (batched)Excellent
Write latency<100ms<10ms

Compression Comparison

Data TypeClickHouseTimescaleDB
Metrics data15-25x10-15x
IoT sensor data20-30x12-18x
Log data10-15x8-12x

Feature Comparison

FeatureClickHouseTimescaleDB
PostgreSQL compatibilityNoFull
Automatic partitioningManual configAutomatic (hypertables)
Continuous aggregatesMaterialized viewsNative support
CompressionExcellentVery good
JOINsBasicFull PostgreSQL
TransactionsLimitedFull ACID
ExtensionsLimitedPostgreSQL ecosystem
Horizontal scalingNativeTimescaleDB multi-node
Managed servicesClickHouse CloudTimescale Cloud

Use Case Recommendations

Choose ClickHouse When:

High-volume metrics and monitoring

-- Fast aggregations on billions of data points
SELECT
    toStartOfMinute(timestamp) AS minute,
    metric_name,
    avg(value) AS avg_value,
    max(value) AS max_value,
    quantile(0.99)(value) AS p99
FROM metrics
WHERE timestamp >= now() - INTERVAL 1 HOUR
GROUP BY minute, metric_name
ORDER BY minute DESC

Log analytics with time-series queries

  • Combined log and metrics analysis
  • High-cardinality tag dimensions
  • Long-term retention with compression

Real-time dashboards at scale

  • Sub-second query response
  • High concurrent query load
  • Grafana integration

Choose TimescaleDB When:

PostgreSQL-based applications

-- Leverage PostgreSQL features
SELECT
    time_bucket('1 hour', timestamp) AS hour,
    device_id,
    avg(temperature) AS avg_temp,
    first(temperature, timestamp) AS first_temp,
    last(temperature, timestamp) AS last_temp
FROM sensor_readings
WHERE timestamp > now() - interval '7 days'
GROUP BY hour, device_id
ORDER BY hour DESC;

Mixed transactional and analytical workloads

  • Sensor data with device management
  • IoT applications with relational context
  • Applications requiring JOINs with reference data

Continuous aggregates for common queries

-- Pre-computed rollups
CREATE MATERIALIZED VIEW hourly_metrics
WITH (timescaledb.continuous) AS
SELECT
    time_bucket('1 hour', timestamp) AS hour,
    metric_name,
    avg(value) AS avg_value,
    max(value) AS max_value
FROM metrics
GROUP BY hour, metric_name;

-- Automatic refresh policy
SELECT add_continuous_aggregate_policy('hourly_metrics',
    start_offset => INTERVAL '3 hours',
    end_offset => INTERVAL '1 hour',
    schedule_interval => INTERVAL '1 hour');

Familiar PostgreSQL ecosystem

  • Existing PostgreSQL tooling
  • PostGIS for geospatial
  • Full-text search integration

Observability Integration

ClickHouse for Observability

ClickHouse powers several observability platforms:

  • SigNoz: Open-source APM using ClickHouse
  • Jaeger: Distributed tracing backend
  • Grafana: Native data source plugin
-- Trace analysis query
SELECT
    trace_id,
    span_name,
    service_name,
    duration_ms,
    status_code
FROM traces
WHERE timestamp >= now() - INTERVAL 1 HOUR
  AND duration_ms > 1000
ORDER BY duration_ms DESC
LIMIT 100

TimescaleDB for Observability

TimescaleDB integrates with PostgreSQL-based tools:

  • Promscale: Prometheus long-term storage
  • pg_prometheus: Prometheus metrics storage
  • Standard PostgreSQL monitoring tools

For comprehensive observability options, see our observability platforms guide.

Cost Comparison

Storage Costs

ScenarioClickHouseTimescaleDB
1TB raw metrics~50GB stored~80GB stored
Monthly storage cost~$2~$3-4
1 year retention~$24~$40-48

Compute Costs

WorkloadClickHouseTimescaleDB
Light queries$100-200/month$150-300/month
Heavy analytics$500-1000/month$800-1500/month

ClickHouse typically offers 30-50% cost savings for pure time-series analytics. For cost optimisation, see our cloud cost guide.

Migration Considerations

PostgreSQL to ClickHouse

When analytics performance becomes critical:

-- Export from PostgreSQL/TimescaleDB
COPY (SELECT * FROM metrics WHERE timestamp > '2025-01-01')
TO '/tmp/metrics.csv' WITH CSV HEADER;

-- Import to ClickHouse
INSERT INTO metrics
SELECT * FROM file('/tmp/metrics.csv', CSVWithNames);

ClickHouse to TimescaleDB

When PostgreSQL compatibility is needed:

-- ClickHouse export
SELECT * FROM metrics
INTO OUTFILE '/tmp/metrics.parquet'
FORMAT Parquet;

-- TimescaleDB import (via PostgreSQL)
-- Use foreign data wrapper or ETL tool

Operational Comparison

ClickHouse Operations

Strengths:

  • Simple architecture at scale
  • Predictable performance
  • Low operational overhead

Challenges:

  • Schema changes require planning
  • Different SQL dialect
  • Smaller ecosystem

TimescaleDB Operations

Strengths:

  • Familiar PostgreSQL operations
  • Mature tooling and ecosystem
  • Easy for PostgreSQL teams

Challenges:

  • PostgreSQL tuning knowledge required
  • Chunk management at scale
  • Resource-intensive for large deployments

Hybrid Architecture

Use both databases for different requirements:

┌─────────────────────────────────────────┐
│              Data Sources               │
└─────────────────┬───────────────────────┘

    ┌─────────────┴─────────────┐
    ▼                           ▼
┌─────────┐               ┌───────────┐
│ Click   │               │TimescaleDB│
│ House   │               │           │
└────┬────┘               └─────┬─────┘
     │                          │
     ▼                          ▼
High-volume               PostgreSQL-integrated
Analytics                 Applications
Real-time Dashboards      Relational Context
Long-term Storage         Transactional Needs

Conclusion

Both ClickHouse and TimescaleDB excel at time-series workloads with different strengths:

Choose ClickHouse for high-volume analytics, real-time dashboards, and scenarios where query performance and compression are paramount. It’s ideal when you don’t need PostgreSQL compatibility.

Choose TimescaleDB when PostgreSQL compatibility matters, you have mixed OLTP/OLAP workloads, or your team has strong PostgreSQL expertise. Continuous aggregates make it excellent for predictable query patterns.

Consider your ecosystem: If you’re already running PostgreSQL, TimescaleDB is a natural extension. If you’re building a dedicated analytics platform, ClickHouse offers superior performance.

For help selecting the right time-series database, contact our team to discuss your requirements.

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