Does Historian need the d2 file archive when used with an SQL database?

Hi all

I am using OpenHistorian with a Postgress SQL database and a small number of PMUs.

The d2 file archive is taking a lot of space as I am using historian to store a number of power system parameters in high resolution (100/frame).

My question is whether openhistorian needs the d2 file archiving too when used with a database. I just want to be able to retrieve data for a couple of power system parameters from a couple of PMU devices and export it to CSV for historical time periods using the web interface of historian. Is the archiving needed for this?

Thanks in advance for any advice.


Hi Stavros,

Yes, in order to export to CSV using the openHistorian web interface, you will need to use the local historian which archives your data in the .d2 files you mentioned. The web interface interacts with the local historian to retrieve data from the archive and put it in the exported CSV files. If you were to use a PostgreSQL database instead, you would need to develop your own process to get the data from there into a CSV file.