Problems with rerendering subcomponent content as sorting

[wwsskkaa]

questions regarding the sorting here:

1. if there is only one row in the table, even the column can be sorted but actually there is some optimization done to prevent the subcomponent under that row to be rerendered again, if there are N rows in the table, each with some subcomponent content but sorting won't change their order, the rerendering will only happen to the subcomponent when their parent rows change position, is this expected behavior?
2. if i want to make sure the rerendering always happen once i click sort, is there a way?