Hi Igniters, As you know, Ignite SQL engine is tightly coupled with the H2 database that provides basic parsing and query execution capabilities. This synergy has worked well for a while until Ignite SQL engine got a much broader adoption for all sort of use cases.
Presently, there is a list of impactful issues and limitations related to memory management, distributed engine optimization, and queries planning that require changes in H2. We've tried to contribute to H2 directly with no significant luck - what's needed for our distributed engine is of no interest to H2 community. At the same time, we can't leave the things as is, as long as these limitations keep Ignite SQL engine from gradual evolution. As a solution, we created an H2 fork [1] and did all of the required changes there. We would be happy to include the fork into Ignite source base, but H2's license (available under dual MPL 2.0 and EPL 1.0) is not compliant with Apache 2.0. However, if Ignite starts using our maven artifacts instead of the standard H2's ones, then the licensing issue is solved. Is the community ready to accept this solution and swap the standard H2 artifact with the one prepared by GridGain? Presently, all of those improvements are available to GridGain customers, but GridGain wants to make all of them be available for Ignite community. And that's the only legal way we've come up with... [1] https://github.com/gridgain/gridgain/tree/master/modules/h2 -- - Denis
