An update after 24-odd hours, so far the database-size incantation seems to be working. Of course this could be just on my setup, or it could stop working next week…
Since the next step will be dealing with the data volumes involved, does anyone know how data accesses are spread across the two? There’s quite a few threads asking about MariaDB + InfluxDB but they all seem to boil down to there are two databases, HA uses them. How does HA use them? For example if I ask for the last week’s worth of data for sensor X, does it come from MariaDB or InfluxDB? If it’s InfluxDB does that mean I can set the retention period for MariaDB to 24 hours? Or does it keep data in both MariaDB and InfluxDB for purge_keep_days, in which case why do I need both?