Stereotypically, attributes of this great princess are applied to all Olgas. Name is particularly popular among Ukrainian Diaspora. There is no difference in how Ukrainians or Russians pronounce the name in their native language, but there is difference is how they spell their names in English. You can see the origin by differed spelling - Olha (Ukraine), Olga (Russian speaking countries, Poland, Latin America).
For short - Olia, Olichka, Olyunia, Olka, Olana.
There are also male name Olga in use in Turkey