It sounds interesting, but what are the actual advantages compared to a standard HTTP client? At what data volume does performance parity begin?

nitpick: this library requires consumer give io callbacks (potentially through the included clickhouse-client.h header), or use the sans-io interface (which clickhouse-c-rs[1] uses to implement tokio layer), which makes it capable of talking over native tcp protocol, http, or stdin/stdout (clickhouse local). ClickHouse has both native protocol[2] & native format[3]

1: https://github.com/ClickHouse/clickhouse-c-rs

2: https://clickhouse.com/docs/resources/develop-contribute/nat...

3: https://clickhouse.com/docs/resources/develop-contribute/nat...