I'm not sure if I've been searching using the wrong keywords, but I've tried so many different ways of wording this and I can't find a relevant answer.
Basically, given a set of circles defined by their centers and radii and a point (x, y), I want to find all circles whose radii cover that particular point.
For example, say I have a website that lists a bunch of delivery restaurants that deliver only as far as a certain radius from their restaurant. I live at (x, y) and I want to run a query in my database that finds all the restaurants that deliver food to my place, so even if a restaurant is in Tokyo and if it claims to deliver within a radius of one light year, it should show up in a Californian's search.
The naive way is just to loop through all restraints in the database and compare the distance and the radius. How is this any different in terms of efficiency from a query that searches for all restaurants lying within a defined circle (typical Yelp problem)?