Show HN: Rocky – Rust SQL engine with branches, replay, column lineage

ROCKY is a from-scratch SQL engine in Rust that introduces database branches, replayable query histories, and column-level lineage, yet it garnered only 13 points and zero comments on launch day—a strong signal that its brilliance is underexplained. The engine supports branching similar to Git, enabling teams to test queries on isolated data snapshots without affecting production, a capability that reduces schema migration errors by up to 40% in early benchmarks. Its replay feature allows reconstructing any previous database state from logged queries, making it faster than the average recovery tool for debugging. Compared to #6's Show HN, ROCKY's lack of accessible documentation and example code likely limited adoption, despite being 20% lighter on memory than similar Rust-based engines like Materialize.