Cardinality Function Confusion

Hey all, I’m struggling to get to the bottom of a high cardinality metric, and I’m hoping to get some clarification on the results I’m receiving when trying to dig into this.

To start, SELECT cardinality('mymetric.count.value') FROM Metric SINCE 24 hours AGO TIMESERIES RAW shows me a graph with between 11 and 12 million every 30 minutes. If I drop TIMESERIES though, I end up with a single value of around 14 million. What exactly am I looking at with each of these queries? I’m assuming without TIMESERIES I’m looking at a total cardinality of 14 million since 24 hours ago, but then why does TIMESERIES show 11-12 million every 30 minutes?

To further my confusion, I use the “exclude” parameter in the cardinality function to narrow things down. First, running FROM Metric SELECT keyset() WHERE metricName = 'mymetric.count.value' to get a list, and then running SELECT cardinality('mymetric.count.value', exclude:{myattributelist}) FROM Metric SINCE 24 hours AGO TIMESERIES RAW. I expect a return of 0 from this query, because I’ve just excluded every attribute from the function, but instead it seems to just roughly cut the results in half - 5-6 million every 30 minutes with TIMESERIES, and around 7 million without.

I feel I must just be misunderstanding this function and/or cardinality as a whole. Any help would be greatly appreciated.