As the name suggests, this file /CumulusMX/data/cumulusmx.db (note case for Linux environments) is only applicable for MX. It contains one table StandardData in the SQLite3 database in this file.
Here is the relevant create table instruction, so this tells you the 17 fields in the file: CREATE TABLE "StandardData"( "Timestamp" datetime primary key not null , "Interval" integer , "OutTemp" float , "LoOutTemp" float , "HiOutTemp" float , "DewPoint" float , "LoDewPoint" float , "HiDewPoint" float , "WindChill" float , "LoWindChill" float , "HiWindChill" float , "InTemp" float , "LoInTemp" float , "HiInTemp" float , "Pressure" float , "LoPressure" float , "HiPressure" float )
It is not documented anywhere I have seen what option you have to turn on in MX to start this database being updated. The file is created when you run MX, it is not included in the release distribution to ensure any data you have in the database table is kept when you install a new MX version.
Could anyone who knows what option in MX updates this file, and in what context use is made of this database, please explain it by amending this article