Virtual feed interval

Hi all,

Does a virtual feed have an interval, and if so how is it determined?
I have 16 kWh PHPFINA feeds that update every 15mn, and I want to have f0-f1-f2…-f15 as a virtual feed.

The resulting feed is really slow when using the feed in a graph with a 900s interval; and if I try to export it with an “Auto” interval I get a 10s interval in the data: is that determined on the fly by the exporter? Or configured into the virtual field?

I initially created the virtual feed from a source feed f0 that was updating every 10s; later I “edited” that first line in the virtual feed config to point to the new f0/15mn feed… is my virtual feed stuck on a 10s interval coming from that initial config?

Thanks!
Franck

… and a related question (an alternative to a virtual feed), I assume that a feed generated by post-processing is not automatically kept up to date?

Would a cron Jon on the emonPi to run the post processing a couple times a day be a good idea?

Thanks!