Workflow and timer job synchronization

Question

I have a SP 2010 workflow that prompts information from the users, and a timer job which reads data from a constantly-updated DB. They both add data to another list item that stores the most recent business information.

Edit: To clarify, these list items are a sort of dashboard that aggregate information from several sources. Thus, both the workflows and the timer job will access the same list item (but the items will be different for different workflow instances). The workflow and the timer job will modify different fields.

Is there any chance of synchronization errors between the concurrent updates? Can user-entered information be lost? How do I go about synchronizing the workflow and timer job, and what other pitfalls should I look out for? Thanks.

Answer 1

There is a chance of a Save Conflict if the timer job saves an edit while the user has the edit screen open. It's really a warning message, but it looks like an error and generally you want to avoid it. Have you looked into external data columns? That is a good way to pull in data from a database without timer jobs.

Answer 2

I don't get your question completely:

• is the data from the workflow stored in the same list as the data from the timer job?

if not, you can go with the BCS and show the database data in an external list.

if the data is stored in the same list: if both methods just both add data, i don't think it will bug out. New items will not overwrite other items that are being added, the SP object model handles it.

My question is: why would you put that two types of information in one list? need to edit it? or do you need to show the combination of data to a user?