Hi. I created a calculated metric to simply count the number of days using the approximate count distinct function. It's been working just fine up until this past week. Count shows 6 days in week instead of 7, even though a breakdown by day shows 7 days? Any ideas why this is happening?
The behavior looks weird. However, please note that the function Approximate Count Distinct isn't 100% accurate. The function uses the HyperLogLog (HLL) method of approximating distinct counts. It is configured to guarantee the value is within 5% of the actual value 95% of the time.
Though, you may want to raise a ticket with us and we will happy to take a look.