first extent and next extent

Hi, I want to know that is there a system table include first and next extent size information ? and how can i keep the origin extent size during dbexport and dbimport easily ? and how can i change the first extent size after dbimport (for i know change next extent size by alter table statement)? -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet