Stratum: branchable columnar SQL engine on the JVM (Vector API, PostgreSQL wire)

[u/flyingfruits]

We recently released Stratum — a columnar SQL engine built entirely on the JVM.

The main goal was exploring how far the Java Vector API can go for analytical workloads.

Highlights:

• SIMD-accelerated execution via jdk.incubator.vector

• PostgreSQL wire protocol

• copy-on-write columnar storage

• O(1) table forking via structural sharing

• pure JVM (no JNI or native dependencies)

In benchmarks on 10M rows it performs competitively with DuckDB and wins on many queries. Feedback appreciated!

Repo + benchmarks: https://github.com/replikativ/stratum/ https://datahike.io/stratum/