Add ClickHouse chDB plugin to provide embedded DB for lightweight data transformations

[Ben8t]

Feature description

Like DuckDB, chDB is an in-memory OLAP engine. It has some advantages, especially a high number of format integration.

• Contribute to the java binding (first iteration can be found here, not sure if relevant or better to start from scratch https://github.com/chdb-io/chdb-java)
• https://github.com/chdb-io/chdb/blob/main/bindings.md

[anna-geller]

Overall, pretty good impression that we can use it well in a dedicated chDB plugin at first — it can belong to the ClickHouse plugin parent category, as Ben suggested.

The plugin should take a query and outputFormat as main properties.

Ideally, we should find a way to:

• output ION file when no outputFormat is specified because then tabular data is output by default
• output ION file when PrettyCompact is used as outputFormat
• dedicated file extension when outputFormat is a specific file extension e.g. our plugin should output a CSV file instead of ION when output_format='CSVWithNames'.

Queries and links I explored are documented here https://github.com/kestra-io/market/tree/main/databases/chdb