Does Workflow 4.5 require SQL Server for persisting state?

Question

I'm reading "Pro WF 4.5" published by APress, which seems to say unequivocally that in order to persist state in a long-running workflow after a server crash/shutdown (anything that'd clear memory), a SQL Server back-end is required for persistence.

A lot of the MSDN stuff I see online seems to contradict this. For example, the article linked below.

https://msdn.microsoft.com/en-us/library/dd851337.aspx

What is the real scoop, from someone actually using WF? TIA.

Answer 1

There is a built in Instance Store for SQL Server (https://msdn.microsoft.com/en-us/library/system.activities.durableinstancing.sqlworkflowinstancestore(v=vs.110).aspx) but there is nothing stopping you creating your own - https://msdn.microsoft.com/en-us/library/ee829481(v=vs.110).aspx

That way you could use any persistence you like.

Answer 2

Implementing your own implementation for durable instance on WF can be done. My experience is that it is difficult to do. I ended up with a provider created by Devart. They created a provider for Oracle databases. You can find more information here https://www.devart.com/dotconnect/oracle/docs/WorkflowInstanceStore.html