Recent history: Difference between revisions

851 bytes removed ,  12:50, 29 September 2022
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#*Table rows, or array elements, will be less frequent (or even missing) for the period before Cumulus is started
#*Table rows, or array elements, will be less frequent (or even missing) for the period before Cumulus is started
#*Cumulus uses current time, read from the computer, in its decision as to where to store each new recent history value set, so it can overwrite existing table rows, or array elements, if date-time matches one that already exists, such as in the hour after when clocks go back.
#*Cumulus uses current time, read from the computer, in its decision as to where to store each new recent history value set, so it can overwrite existing table rows, or array elements, if date-time matches one that already exists, such as in the hour after when clocks go back.
=How are recent history values stored?=
Depends on the release you are running:
* Release 3.12.0 onwards: Held in [[cumulusmx.db|RecentData table in cumulusmx.db]] (uses SQLite). There are many software tools available that can read/edit SQLite3, this is not the place to get too technical, but take a look at '''sqlitebrowser''' in a Linux environment, and '''phpLiteAdmin''' in Microsoft Windows.  Also, you could use any application that can read ODBC files (e.g. Libre Office's Base functionality) can read the MX databases.
* Cumulus 2: Was held in an external SQLite database, together with other data that Cumulus 1 had held in text files, as above
* Releases 3.0.0 to 3.11.4: Held in a SQLite database table that is stored in-memory within MX code
* In the legacy Cumulus 1, the values were stored in an array held within the Cumulus code.


=What happens when I need to stop and restart Cumulus?=
=What happens when I need to stop and restart Cumulus?=