Summary statistics are kept forever (perhaps in 5-10 years we’ll need something to clear those out too!)
If your only reason to use something like influxdb or prometheus (or mysql?) was to have any sort of data past 10 days, it’s very likely that you don’t need those services anymore.
For myself, I have multiple HA installs. I’ll keep something more robust for home (where I’m also ingesting lots of non-HA data). For the other install, the main point of influx was for checking indoor temperatures. In that case, summary stats at a 1-hour resolution is perfect, so I can reduce complexity and drop influx.
Just thought I’d share a quick screenshot that shows the automatic transferal from history to Long Term Statistics. These are CO2 readings from the AirGradient I bought this month, and the first day or two have been changed automatically since they are past 10 days old now. When hovering over the graph, it clearly says the source (history/long term).
Sorry to dig up that thread. But I’m still struggling with how I can access LTS for using it with templates.
For example I want to calculate the average daily driven kilometer of the last 30 days from an odometer sensor of my car.
Using a statistics helper sensor with characteristic “change” and max_age of 720 hours returns the change of the last 10 days only. Therefor I assume it’s not accessing the LTS data. I can see the LTS data from the History screen though.
