Query tag execution mode question

We recently upgraded to ignition 8 and noticed some of our query tags were not updating. I didn’t notice the option in 7.9 but in the new tag properties window the default execution mode was set to “Event”.
It seems like the problem was fixed by changing these to a fixed rate execution but i was wondering what the event would be for the query tags to be updated internally, as the tag would not necessarily see a change in value unless the query was run.

The event would be a change in an input parameter to the query. If you don’t have any input parameters (constant SQL) then you would need a fixed rate.

The upgrade process could be a bit smarter about this, I would think.