ecto_ch

Why it's ranked here

A strong fit for Elixir teams already committed to Ecto and ClickHouse. It covers more than basic querying: migrations, typed bulk ingestion, schema generation, database settings, and ClickHouse-specific SQL behavior all receive explicit support. The repository also tests query compilation and real database integration.

What's good

Type handling is unusually concrete. The custom Ch type removes ambiguity for integers, decimals, maps, arrays, nullable values, IP addresses, fixed strings, and enums. Schemaless inserts can supply an explicit field-to-type map. Migrations expose engines, cluster options, ordering, defaults, nullability, and comments instead of hiding ClickHouse concepts.

Tradeoffs

This is not a drop-in relational adapter. Ordinary Ecto updates raise because ClickHouse lacks standard update statements; the alternative uses an administrative mutation with a performance cost. Some common Ecto types are ambiguous and discouraged. RowBinary inserts ignore column default expressions, so schema defaults may not behave as expected.

How to use it well

Choose it for an Elixir application that already models data access through Ecto and needs typed analytics queries or bulk ingestion into ClickHouse. Define ClickHouse types explicitly, treat mutations as exceptional, and test migration options against the target server. It does not replace ClickHouse itself or provide a general relational database layer.

Observed

License

MIT

Primary language

Elixir

Packaging

Hex package installed as a Mix dependency

Interface

Elixir library implementing an Ecto adapter, plus a Mix schema-generation task

Core dependencies

Ch driver and Ecto SQL

Test structure

Repository includes SQL compilation tests and live ClickHouse integration tests

Local test service

Docker Compose configuration exposes ClickHouse on port 8123