What's the system impact on running a filter subscription across all users?

[Larry Woodley]

I've got a team requesting an email alert to be sent out to users when an issue due date is approaching. In order to ensure I capture whichever user may be attached to that ticket, I'd have to run a filter on project and due date, including assignee = currentUser() and attach the resulting subscription to the jira-users group. Is there an associated system load with running this search along all users?

[Phill Fox]

I would always reduce the number of issues to a minimum that are returned by any filter being used for subscriptions. For example using the condition of resolution is EMPTY to remove any issues that are already completed. 

[Vasiliy Zverev]

I have 450 users on my instance and several similar subsriptions and there is no trouble. But I set it on different time (differs for 15 min) in order not to create long letter chain.