Migrate to ClickHouse

Migrate from Oracle to ClickHouse

Move the reporting and data warehouse workloads off Oracle and onto ClickHouse. Faster queries over decades of history, no licence audits, and a platform your team can actually run.

How the migration works
Sub second
Queries over billions of rows, from columnar storage and vectorised execution.
50%+
Cost savings observed in the migrations we have delivered from SQL Server, OpenSearch and Snowflake.
100s
Of concurrent users served with consistent latency, so analytics can go into your product.
Anywhere
Open source. Run it on any cloud, on premise or as ClickHouse Cloud.
Why teams move

Why Oracle users come to us

Oracle data warehouses tend to be old, large and business critical. They hold years of sales, finance or operational history and a tangle of PL/SQL, views and scheduled jobs that nobody wants to touch. They also come with licensing that makes every scaling decision a commercial one.

The symptoms are familiar. Reports that take minutes, memory and tablespace problems as the history grows, overnight batches that run into the morning, and an annual true up that keeps getting bigger. Meanwhile the business wants intraday numbers and self service dashboards, and the warehouse cannot keep up.

We migrated twenty years of sales data for a food manufacturer and retailer from a legacy Oracle warehouse to ClickHouse, resolving the performance and memory issues and giving them a real time warehouse in place of a nightly one. The same approach applies to most Oracle reporting estates.

Sound familiar?
  • [01]Reports and BI queries over large fact tables take minutes and tie up the database.
  • [02]Licensing cost dictates the hardware, and every expansion needs a commercial negotiation.
  • [03]Nightly ETL windows are overrunning and intraday reporting is not possible.
  • [04]Memory, tablespace and partitioning issues as historical data accumulates.
  • [05]Oracle skills are scarce and expensive, and the estate is hard to change safely.
What changes

Oracle to ClickHouse: faster, cheaper, simpler

ClickHouse is the fastest open source analytical database on the market. These are the differences that matter most for teams coming from this platform.

[01]

Twenty years of history, queried in a second

ClickHouse compresses historical data heavily and only reads the columns a query needs, so long history stops being a performance problem. Full table scans over billions of rows are routine.

[02]

The licence bill goes away

ClickHouse is open source. Run it on your own hardware, in your cloud or as a managed service, and pay for compute and storage rather than cores and options.

[03]

Real time replaces the nightly batch

With CDC feeding ClickHouse continuously and materialised views maintaining aggregates as data lands, reports reflect the business as it is now rather than as it was at midnight.

[04]

A platform your team can run

Standard SQL, open tooling and a large community. ClickHouse is far easier to hire for and to operate than an Oracle estate, and we support it if you would rather not.

How we migrate

Accelerated migration with CDC

For Oracle we use Supermetal, which replicates from Oracle into ClickHouse with an initial load followed by continuous change capture, so the warehouse can be migrated and validated while Oracle stays live. PL/SQL logic, views and scheduled jobs are translated to ClickHouse SQL and materialised views, and the two platforms run side by side until every report reconciles.

  1. 01

    Assess

    We review the schemas, the query workload and the cost of the current platform, then agree the scope, the target architecture and the business case before anything is built.

  2. 02

    Design the ClickHouse schema

    Tables are redesigned for columnar storage rather than copied across one to one. Sorting keys, partitioning, codecs and materialised views are chosen against your real queries.

  3. 03

    Load and replicate

    Historical data is bulk loaded, then changes are streamed continuously so ClickHouse stays in line with the source for as long as the two need to run side by side.

  4. 04

    Run in parallel

    Dashboards, applications and reports are pointed at ClickHouse and validated against the source. Performance and cost are measured rather than assumed.

  5. 05

    Cut over

    Workloads move across in stages, the old platform is scaled down and the remaining spend is retired. Nothing is switched off until the numbers reconcile.

  6. 06

    Support

    After go live we can monitor the environment, tune it as the workload grows and provide an escalation path under SLA through our proactive support service.

Tooling we use
Supermetal

A high performance CDC engine from supermetal.io that ships as a single binary and replicates from Postgres, MySQL, SQL Server, Oracle and MongoDB into ClickHouse, including self hosted clusters.

Parquet and object storage

Warehouse exports land in S3 or GCS as Parquet or Iceberg. ClickHouse reads them directly with its table functions, or ClickPipes keeps ingesting new files as they arrive.

We are tool agnostic. The right choice depends on whether you are going to ClickHouse Cloud or self hosted, how much control you want over the pipeline and what else is in the stack. Zero downtime is the norm, not the exception.

Beyond the migration

One database, many use cases

Moving off Oracle is usually the start. Because ClickHouse is so versatile, the same platform tends to pick up more workloads once it is in place.

Real time analytics

Dashboards and embedded analytics over data that is seconds old, served to many users at once.

Data warehousing

A warehouse that is fast enough to query directly, without the overnight batch or the cube layer.

Observability

Logs, metrics and traces at a fraction of the cost of Datadog, Splunk or Elastic, with ClickStack on top.

Time series

Market data, IoT, telemetry and events at hundreds of thousands of rows per second with long retention.

Search and security analytics

Full text search, SIEM and threat hunting over high volume event data using plain SQL.

Agentic AI

A data platform fast and cheap enough for agents that turn one question into dozens of queries.

Related work

Migrations we have delivered

Manufacturing & Retail

Helping A Food Manufacturer And Retailer Deliver A Real Time Data Warehouse Using ClickHouse

Migrating 20 years of sales data from a legacy Oracle data warehouse to ClickHouse, resolving performance and memory issues while accelerating business intelligence.

Automotive

Migrating An Automotive Analytics Platform From SQL Server To ClickHouse

Replatforming a dealer management analytics product from SQL Server to ClickHouse, delivering observed cost savings of 50%+.

Further reading

Ready to move off Oracle?

Start with a short call. We will look at your schemas, queries and current spend, tell you honestly whether ClickHouse is the right fit, and put a number on the performance and cost you can expect.

Support after go live