Sensor history locked on the same value!

Hi, since yesterday the sensor history no longer works on all sensors
A solid line is shown with the same value on the chart, what happened?Immagine1

This error appears in the log file "database disk image is malformed".
Fixed it seems that the DB file sometimes gets too big or gets corrupted !!
Solution: delete home-assistant_v2.db file and restart

Here is how to delete the DB file.