big o - When does one typically prefer the little-o instead of the big-O? -

i understand difference between big-o , little-o, wonder when/why 1 choose little-o on big-o particular situation (and opposite).

you can chose describe algorithm or requirement using little-o notation when want emphasize difference big o, or if want ensure "something better than..."

a naive example - if need 3rd party create library you, , want ensure query time sublinear, mathematical notation sublinear o(n), o(.) little o notation.