Hello Thomas, I have created a event store for arangodb using Foxx. https://github.com/diegogub/arangodb-es
Are you talking about the event ID or entity ID? For entity ID you could use a small read collection with all unique ids, and read before creating the entity. Regards, El jueves, 18 de agosto de 2016, 9:15:58 (UTC-3), Thomas Weiss escribió: > > Hi everyone, > > Continuing on a topic I briefly mentioned before on Slack... I'm currently > prototyping some event-sourcing on ArangoDB; I think ADB is a great > platform for that thanks to Foxx and I hope to be able to blog about that > once everything settles down. > > Event-sourcing in a nutshell: updates to the DB are done by > (1) logging an event that describes how the DB is intended to be modified > (2) applying this event to execute the modifications against the DB > > I've managed to design most of those principles in Foxx, but I've an issue > when the update is the creation of an entity. Following the event-sourcing > "theory", the event log is the single-source-of-truth so the event shall > completely describe the intended update. So when creating an entity, the > corresponding event shall contain its ID, which means that I need to define > an ID (or rather a _key in ADB) that will be guaranteed to be valid when > the entity is inserted in the DB. Applying an event cannot fail and events > are immutable. So I'm wondering if there is a way to generate a _key that > will be guaranteed to be valid (i.e. not already used) - considering that I > can run all that in a transaction. > > All suggestions welcome! > > Thanks in advance, > Thomas > -- You received this message because you are subscribed to the Google Groups "ArangoDB" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
