Software architecture design for static code analysis tool

I don’t know whether this is the right place to ask but I have a question. How does the static code analysis tools store and show us the details of each line and file of any repo like that of Sonar, CAST, Coverity, etc ?

Here is what I understood after seeing and running Sonar locally:

Sonar scanner runs in the build machine, reads the coverage reports and probably do analysis on top of it and send it to Sonar server which then stores it and shows us reports through UI Dashboard.

Here is what I had trouble understanding:

How do they store the analysis of each line, file, and module in their database? Do they store each line of the project in their database tables? Won’t it make the database heavy because a single repo contains 1000s of lines of code and some tools also provide version control on top of it as well.

Any help will be highly appreciated.