A temperature sensor on a machine takes one reading a second. When the machine runs hot, the fan has to come on right away, whether or not the plant’s Wi-Fi is working. In the Alpha demo this device runs the AltSql engine on 64 KB of flash with 1,048 bytes of engine RAM, and it makes that call by itself.

The run covers one simulated hour. Wi-Fi drops out from minute 20 to minute 35. Two gateways listen: gateway A receives every record, and gateway B, which stands in for a constrained link, receives only the minute summaries and the fan state.

Medicines and fresh food travel in refrigerated trucks, and many loads must stay between 2 and 8 °C for the whole trip. When the cooling fails, somebody has to know how long the load was warm and how warm it got, even if the truck is nowhere near a mobile signal at the time. In the Alpha demo a logger inside the load keeps that record itself. It runs the AltSql engine on 512 KB of flash with 920 bytes of engine RAM.

A soil sensor in a field usually runs on a battery and talks over a radio that carries a few dozen bytes a day. It cannot wait for a server to tell it when to water. In the Alpha demo the sensor decides for itself when to open the irrigation valve, and it reports to the farm office in one small radio message a day. It runs the AltSql engine on 32 KB of flash with 672 bytes of engine RAM.