HTAP & Rapid

The column store

Rapid is an in-memory columnar engine (IMCS) that keeps a mirror of your InnoDB tables. Analytical scans read the column store; short OLTP transactions keep running on the row store.

Two propagation channels

Committed changes reach the column store over two paths: the redo log for durability, and a DML notification path for latency. Analytical reads see transactional writes without a sync window you have to reason about.

MVCC version linking

Version linking runs inside the column store, which is what lets a long analytical scan and a short transaction coexist on the same table.

Loading a table

mysql> ALTER TABLE lineitem SECONDARY_ENGINE = RAPID;
mysql> ALTER TABLE lineitem SECONDARY_LOAD;

Once loaded, the optimizer routes queries by cost. No hints, no application change.