(Not OP, but I feel like I've seen this phenomenon before.) In C, the natural idiom would be to read in a giant file line by line, doing something with each line and eventually doing something else based on some summary of everything read so far. Lots of dumb SQL code also does something like this, e.g. by generating some ginormous join and then whittling it down to something usable. Better SQL code filters before the join, and often uses indexes to do so.

There are people in this world who do things like use cursors in place of joins, for example.