Update Visitor Logs Retroactively for a Site

Support & Bugs
1

I want to update visitor logs to add a value to a custom dimension that is currently empty.

Is it possible to do this in SQL and then invalidate the report for the given site?

I was thinking of something like this:

UPDATE log_link_visit_action 
SET custom_dimension_2 = 'my_value' 
WHERE idsite = 'myidsite'

Then invalidate the report.