This is a breaking change release: The legacy service grid implementation was removed.
New Apache Calcite-based SQL engine
We've implemented a new experimental SQL engine based on Apache Calcite. Now it's possible to:
The current H2-based engine has fundamental limitations. For example:
- some queries should be splitted into 2 phases (map subquery and reduce subquery), but some of them cannot be effectively executed in 2 phases.
- H2 is a third-party database product with not-ASF license.
- The optimizer and other internal things are not supposed to work in a distributed environment.
- It's hard to make Ignite-specific changes to the H2 code, patches are often declined.