As of April 26, 2022, Apache Ignite 2.13 has been released. You can directly check the full list of resolved Important JIRA tasks but here let's briefly overview some valuable improvements.
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:
- Get rid of some H2 limitations;
- Optimize some query execution.
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.