This article details two often inquired about limitations dealing with the included HSQL database in Flux.

Flux is packaged with an in-memory HSQL database that, for most intents and purposes, serves as a reasonable database to evaluate Flux with. When implementing a de facto installation of Flux, it is highly recommended that a more robust, external database be used. We test and support Oracle, MYSQL, SQL Server 2005+, Sybase and DB2. We recommend you switch to a ?real? DBMS as, the HSQL database is known to conflict with two major areas of Flux.

The HSQL database will only permit one job to be running on an engine at a time. This heavily impedes workflow execution and may even lock your engine

Additionally, the single job running on the engine will not be persisted on disposal. That means every time you shut down Flux, you will need to re-export all tasks to the engine.

For information on installing and configuring an external database with Flux, see doc\quick_start_guides\quick_start_database\general-database-setup.pdf