Build a visual showing evolution of a parameter based on two databases with different periods oftime

Hi!, I think it is a very simple question but I guess if there is a simpler approach to sort this out than the one I'm thinking in.

I have two databases in my Power Bi model.

1 - A plain database with sales information from period 2010-2018 (local excel file with historical information that is not being updated anymore)

2- A sharepoint database with the information from 2019-on (this is live and is currently being updated and automatically refreshed on the Power Bi model)

And one dictionary:

1 - Calendar, automatically generated with days from Jan 1st 2010 to the last day that it find in the database 2.

Most of the visuals I have in my model are linked to the 2nd database to show current KPIs but I want to add one visual showing the evolution of sales by month from 2010 to now.

I have both databases linked by a dictionary with dates (DIC_DATES) so I know I have to put the DIC_DATES (Date) in the X axis but how can I do to put the sales for the whole period on the Y axis?

The only approach I can imagine is to do a query to append both databases in a new one that shows all the information 2010-today and then do the visual from there but I want to avoid generating a new huge database.

Is there a simpler approach?

Thanks!!