We store data at 1 minute granularities for the duration specified in your account package.
Note that when picking graph date ranges, any selection over 1 day will be rolled up into hourly values to avoid overloading the browser with too many data points. Choose a time window shorter than 1 day to see the minute data.
When you delete a device or service from your account, the item is removed from your inventory and you won't be able to access the data, but the metrics data itself is still stored in our time series backend to be deleted asynchronously. It is removed from this datastore after 1 week but will be retained in our backups for up to 90 days.