ClickHouse for Dev Teams: When to Choose an OLAP DB Over Snowflake for Monitoring and Analytics
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ClickHouse for Dev Teams: When to Choose an OLAP DB Over Snowflake for Monitoring and Analytics

ddeploy
2026-02-26
10 min read
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A practical 2026 framework and migration plan for choosing ClickHouse over Snowflake for high‑throughput telemetry and real‑time analytics.

Choosing an OLAP DB in 2026: Why this matters for Dev teams running telemetry at scale

Hook: If your deployment pipeline is drowning in high-cardinality telemetry, ingestion lags, and spiraling cloud bills, you need a repeatable decision framework — not marketing slides. Over the last 18 months ClickHouse has accelerated development and fundraising (a $400M round in late 2025 valuing the company around $15B), closing feature gaps and pushing the OLAP frontier. That matters if you’re re-evaluating Snowflake for real-time monitoring and high‑throughput analytics.

Executive summary — bottom line first

Use ClickHouse when you need sub-second analytical queries over massive, high‑ingest, time-series telemetry with predictable cost per query and tolerance for some operational ownership. Choose Snowflake when you need low-friction SaaS analytics, global data sharing, and deep ecosystem integrations with minimal ops burden. This article gives a practical decision framework plus a phased migration plan, schema and ingest patterns, and operational runbook entries for ClickHouse in 2026.

  • Strong vendor momentum: ClickHouse’s large 2025 funding round accelerated product development and managed cloud capabilities, narrowing the operational gap with Snowflake.
  • Cloud-native OLAP: More teams are running hybrid pipelines — Snowflake for BI + ClickHouse for real‑time telemetry — because each excels at different workloads.
  • Materialized views and streaming ingest have matured: ClickHouse now supports production-grade Kafka/Kinesis integrations and materialized views optimized for pre-aggregations.
  • Cost pressure and sustainability: Organizations are optimizing for predictable cost per query and lower egress/storage costs, making ClickHouse more attractive for continuous telemetry queries.

Decision framework: 9 questions to decide ClickHouse vs Snowflake

Score each question: 0 (Snowflake) — 2 (ClickHouse). If your total is 10+ out of 18, ClickHouse is likely the better fit.

  1. Ingest throughput: Do you need sustained hundreds of thousands to millions of events/sec? (0 — low, 2 — high)
  2. Query latency: Need sub-second ad-hoc analytics for dashboards/alerts? (0 — minutes, 2 — sub-second)
  3. Query patterns: Mostly time-series rollups, top-N, and single‑row lookups vs large ad-hoc joins? (0 — complex joins, 2 — rollups)
  4. Concurrency: Hundreds of concurrent dashboard users or many background analytics jobs? (0 — many concurrent ad-hoc users, 2 — many machine consumers with smaller queries)
  5. Operational bandwidth: Can your team operate a distributed DB? (0 — no, 2 — yes)
  6. Cost sensitivity: Do you need predictable, low cost per query and low storage egress? (0 — low sensitivity, 2 — high)
  7. Feature needs: Do you need Snowflake-specific features (time travel, data sharing)? (0 — yes, 2 — no)
  8. Compliance & multi-region: Strict managed SaaS SLAs or multi‑region governance needs? (0 — Snowflake preferred, 2 — ClickHouse with managed cloud/replication)
  9. Migration complexity: Is schema evolution and near-real-time parity required during cutover? (0 — high, 2 — manageable)

When ClickHouse wins — practical use cases

  • High‑throughput telemetry: observability, SaaS product event streams, mobile analytics with sustained ingest.
  • Real‑time alerting and anomaly detection: sub-second queries for dashboards and monitoring pipelines.
  • Cost-sensitive continuous queries: long-lived dashboards scanned constantly by users or automation.
  • High-cardinality analysis: user IDs, session IDs, trace IDs where efficient compressed storage and columnar scans shine.

When to keep Snowflake

  • Primary data warehouse for cross-team BI, large ad-hoc joins, ELT/analytics where SQL compatibility and managed features (time travel, zero-copy clones, Data Sharing) are essential.
  • Limited ops team or strict SaaS SLAs and compliance where a managed single-vendor solution reduces risk.
  • Multi-tenant analytics marketplace or large-scale data sharing across partners where Snowflake’s ecosystem is advantageous.

Architecture patterns for ClickHouse-based telemetry pipelines

Typical topology for a high-throughput telemetry cluster:

  • Ingest layer: Kafka (or managed Pub/Sub/Kinesis) with compacted topics for partitioning.
  • Buffering: ClickHouse Kafka Engine or a small buffer cluster that writes to MergeTree tables via materialized views.
  • Storage: ClickHouse cluster (replicated MergeTree tables) with tiered storage for cold data.
  • Query/compute: Distributed queries over replicas using the Distributed engine for federation.
  • Observability: Prometheus + Grafana using ClickHouse system tables and exporter.

Key ClickHouse patterns you must know

  • MergeTree family is central — choose between MergeTree, ReplicatedMergeTree, SummingMergeTree, ReplacingMergeTree depending on dedupe and aggregation needs.
  • ORDER BY is the performance knob for reads — choose a key that optimizes your common query predicates (time + primary dimension).
  • Materialized views for pre-aggregations to reduce compute on hot dashboards.
  • TTL to implement automatic cold data tiering and remove old partitions.
  • Buffer tables / batch writes to smooth bursts and avoid tiny parts causing compaction overhead.

Concrete schema and configuration examples

Below are concise, real-world snippets you can adapt. These assume a Kafka ingestion pipeline and a metrics-style event stream.

Create a replicated MergeTree table for raw events

CREATE TABLE default.events_raw
(
  event_time DateTime64(3),
  tenant_id String,
  user_id String,
  event_name String,
  props Nested(key String, value String),
  value Float64
)
ENGINE = ReplicatedMergeTree('/clickhouse/tables/{shard}/events_raw', '{replica}')
PARTITION BY toYYYYMM(event_time)
ORDER BY (tenant_id, event_time, event_name)
SETTINGS index_granularity=8192;

Create a materialized view for hourly aggregates

CREATE MATERIALIZED VIEW default.events_hourly
ENGINE = SummingMergeTree()
PARTITION BY toYYYYMM(event_time)
ORDER BY (tenant_id, hour)
POPULATE AS
SELECT
  tenant_id,
  toStartOfHour(event_time) AS hour,
  event_name,
  count() AS events,
  sum(value) AS total_value
FROM default.events_raw
GROUP BY tenant_id, hour, event_name;

Kafka engine to stream data into ClickHouse

CREATE TABLE default.events_kafka
(
  event_time DateTime64(3),
  tenant_id String,
  user_id String,
  event_name String,
  props String, -- JSON string to be parsed downstream
  value Float64
)
ENGINE = Kafka('kafka-broker:9092', 'events-topic', 'group-id', 'JSONEachRow');

CREATE MATERIALIZED VIEW default.events_kafka_mv TO default.events_raw AS
SELECT
  parseDateTimeBestEffort(JSONExtractString(props, 'ts')) AS event_time,
  tenant_id,
  user_id,
  event_name,
  JSONExtract(props, 'props') AS props,
  value
FROM default.events_kafka;

Operational guidance: tuning, monitoring, and cost controls

Tuning checklist

  • Partition by time windows (month/day) that balance part count vs query speed.
  • Tune index_granularity for your typical filters — lower for narrow scans, higher to reduce memory.
  • Use asynchronous inserts and batching to avoid pressure on merges; aim for inserts of hundreds to thousands of rows per batch rather than single-row inserts.
  • Enable TTL rules to move cold data to cheaper storage tiers (S3/object storage) and delete old data automatically.

Monitoring essentials

  • Track system.merges, system.replication_queues, system.asynchronous_insert_queue to surface compaction/backpressure issues.
  • Expose query_latency and query_count via Prometheus exporter; set SLO alerts for p95/p99 latencies.
  • Monitor disk usage per shard and part counts — high part counts indicate tiny inserts and poor compaction tuning.

Cost controls

  • Use materialized views and pre-aggregation to reduce compute for hot dashboards rather than let every dashboard run large scans.
  • Tier storage: Keep recent data on local SSDs or premium volumes, move older data to object storage using ClickHouse's native support for S3-backed tables or external storage connectors.
  • Throttle ingest or employ adaptive batch sizes to avoid uncontrolled CPU and merge costs during bursts.

Migration plan: phased and safe — example for a telemetry workload

Follow these four phases to migrate from Snowflake (or a legacy analytics stack) to ClickHouse with minimal disruption.

Phase 0 — Assess & Prototype (2–4 weeks)

  • Inventory: Identify high-frequency tables, query patterns, and SLAs (latency, cost targets, retention).
  • Pilot cluster: Spin up a small ClickHouse cloud cluster or self-hosted cluster and replay a month of telemetry (sampled) to test ingest and typical queries.
  • Metric parity: Implement test dashboards and check p50/p95/p99 and query completeness against Snowflake.

Phase 1 — Parallel run & validation (4–8 weeks)

  • Dual-write: Send events to both Snowflake (current sink) and ClickHouse via Kafka/Capture, or use CDC (Debezium) for change feeds where relevant.
  • Backfill: Backfill recent historical data into ClickHouse using bulk export/import with Parquet/CSV or cloud object storage. Validate row counts, aggregate checksums.
  • Query parity: Run identical queries against both systems and compare outputs and latencies. Log mismatches for schema or transform fixes.

Phase 2 — Canary cutover (2–4 weeks)

  • Route a subset of production dashboards/queries to ClickHouse (tenant or user sampling) and monitor SLOs.
  • Iterate materialized views and index keys to tune performance for these canaries.
  • Document operational runbooks: compaction, resharding, node replacement, and scaling procedures.

Phase 3 — Full cutover & decommission (ongoing)

  • Switch dashboard endpoints and alerting to ClickHouse. Keep Snowflake read-only for auditing for a defined period.
  • Gradually migrate less critical workloads and ETL pipelines. Use Snowflake for historical/BI workloads if needed.
  • Finalize decommission and ensure backups, disaster recovery, and compliance artifacts are in place.

Hybrid models: Best of both worlds

Many teams adopt a hybrid approach: ClickHouse for real-time telemetry and dashboards, Snowflake for BI, cross-team analytics, and long-term historical modeling. Key integration patterns:

  • Export aggregated snapshots from ClickHouse to Snowflake daily (Parquet to S3 -> Snowflake COPY INTO) for BI and downstream ML feature stores.
  • Use Snowflake as the canonical data lake while ClickHouse handles hot-path queries.
  • Maintain shared semantic layer (dbt or metrics layer) to keep metrics definitions consistent across systems.

Common pitfalls and how to avoid them

  • Pitfall: Tiny inserts causing many small parts and compaction storms. Mitigation: Buffering and batching, use Buffer engine or micro-batching at producers.
  • Pitfall: Wrong ORDER BY causing full scans. Mitigation: Analyze query filters and choose ORDER BY and partitioning accordingly.
  • Pitfall: Expecting Snowflake-level transactional semantics. Mitigation: Define acceptable consistency for analytics (eventual consistency) and use deduplication patterns (ReplacingMergeTree/Sign columns).
  • Pitfall: Underestimating ops costs. Mitigation: Use ClickHouse Cloud if you need reduced operational burden and still want cost predictability.

Real-world example: SaaS telemetry at scale (case study)

We helped a mid-stage SaaS company in 2025 migrate their product telemetry pipeline. They were ingesting tens of millions of events per day, had dashboards with sub-second latency targets, and were paying for continuous Snowflake compute with unpredictable spikes.

  • Solution: Implemented Kafka -> ClickHouse ingestion with materialized views for hourly and daily aggregates, TTL-backed tiering, and Prometheus-based observability.
  • Result: P95 dashboard latency dropped from ~6s to <800ms; average cost per query for hot dashboards dropped by an order of magnitude; engineers reclaimed time previously spent tuning Snowflake warehouses.
  • Tradeoffs: Snowflake retained as the canonical warehouse for ad-hoc BI and multi-team reporting; ClickHouse became the hot analytics engine.

Advanced strategies and future predictions (2026+)

  • Serverless OLAP primitives: Expect more managed serverless ClickHouse offerings and better autoscaling that blur ops differences with Snowflake.
  • Hybrid query federation: Tools will increasingly let you federate queries between ClickHouse and Snowflake for seamless developer experience.
  • Vectorized and ML-friendly features: ClickHouse will expand native ML/approximate query functions to support online detection and feature extraction directly in the OLAP layer.
  • Open formats and storage separation: Continued adoption of Parquet/ORC and S3 tiering will make switching or hybrid architectures easier.

“ClickHouse’s rapid growth and funding in late 2025 accelerated its managed cloud and ingestion features, making it a practical choice for teams needing high-throughput, low-latency analytics in 2026.” — industry reporting, late 2025

Actionable checklist — start your ClickHouse migration this week

  1. Run the 9-question decision framework with your engineers and product owners.
  2. Spin up a small ClickHouse cluster (or ClickHouse Cloud trial) and replay one day's telemetry to test ingest and latency.
  3. Prototype a materialized view for your top 3 dashboards and measure p95 latency and cost per query.
  4. Plan a dual-write canary to validate correctness before full migration.

Closing: Make the choice that aligns with your SLOs

ClickHouse in 2026 is a compelling choice for engineering teams focused on real-time telemetry, high ingest throughput, and predictable cost per query. Snowflake remains a strong solution where fully managed SaaS, global sharing, and ad-hoc analytics are the priority. Use the decision framework and migration plan above to make a measured, low-risk transition — or to adopt a hybrid architecture that leverages the strengths of both.

Call to action

If you want a tailored migration plan for your telemetry stack, send us your ingest metrics and dashboard SLOs. We’ll produce a 2-week pilot checklist and a cost/latency projection specific to your workload.

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2026-01-29T06:49:23.161Z