Hi all! I'm trying to do a count distinct metric. We're trying to measure "unique user follows" aka, for a given user in a control/treatment group in this experiment, how many new, unique follows do they add w/in the experiment time window. There's probably a way to smooth out repeat follows that gets close-ish to a count distinct (e.g. some kind of rolling window that grabs the first follower/followee event in a given 7-day span or something similar). But we also have another use case for this type of metric where that kind of pre-growthbook modeling wouldn't work so well. Any ideas about how to do this in growthbook? And/or I'd love to add a feature request for this type of metric!

Hi Quinn. Are you trying to de-duplicate multiple of the same follow during an experiment? Or are you trying to exclude follows that are repeats of ones done before the experiment started?

Multiples of the same follow during the experiment, most of which are from people following/unfollowing/refollowing in quick succession.

I think this is almost possible in GrowthBook. We let you specify the per-user aggregation (defaults to

SUM(value)

). You could in theory do something like

COUNT(distinct follow_id)

instead. However, we currently don't let you add custom columns like

follow_id

. I think adding support for that would be fairly simple though.

Ah cool! Where can I change the per-user aggregation? I don't see it in the "edit metric" view EDIT: Ah, found it! You have to switch to the "Query Builder" in Edit metric > Query Settings