Consider using Neo4j for the storage

[dcoraboeuf]

Using Neo4J instead of H2 could help in 1) reducing the footprint of the database storage 2) simplifying the maintenance of the schema. Ontrack structure is actually a graph of relation ships between different entities.

This would need to be done for a version 4 of Ontrack, with a necessary migration step from the H2 database to the Neo4j graph database. This could be done by a tool and not necessarily from within the Ontrack application.

In a first phase, only add a module, in versions 2 & 3, to export Ontrack data as a set of CSV files, suitable to be imported in a Neo4j database.

When the export is mature and well tested, start creating a version 4 to use Neo4J as backend.