ClickHouse

License	FOSS problems	Maintenance	SSO	Users	Tested
Apache-2.0Permissive license. Like MIT, but each contributor grants users a patent licence covering their contribution, preventing later suits.	—	Active	—	Unlimited	❌

Description

ClickHouse is a column-oriented database built for fast aggregation over very large datasets — billions of rows scanned quickly — rather than the row-by-row transactional workload Postgres or MySQL are built for.

Features

• Column-oriented storage — reads only the columns a query actually touches, rather than whole rows, making wide-table aggregation far cheaper than a row-oriented database.
• Billions of rows, scanned quickly — built specifically for large-volume analytical queries, not transactional lookups.

Usage patterns

• Log aggregation, metrics, and usage analytics — a genuinely different shape of problem than the other databases in this catalog: nothing here is meant to hold an application's live state. If self-hosted analytics or observability tooling — the kind evaluated in Monitoring — ever needs a backing store of its own, this is the shape of tool for it, not another Postgres instance.
• Not a general-purpose application database — the wrong tool for anything that needs row-level transactional writes.

License and governance

Apache 2.0 — permissive, with ClickHouse Inc. selling a managed cloud on top rather than gating the open-source engine itself.

Conclusion

Why you would — the right shape of tool if a specific analytics or observability need at real volume ever shows up: log aggregation or usage analytics that would genuinely outmatch what a row-oriented database can do efficiently.

Why you wouldn't — nothing in this project currently produces data at a volume that would justify it. Running an OLAP database for a dataset that fits comfortably in Postgres is pure overhead — another service to patch and back up for no real gain. Worth revisiting only if a specific tool genuinely needs it as a backend, not before.