risingwave_frontend::optimizer::rule::over_window_to_topn_rule

Function handle_rank_preds

Source 
fn handle_rank_preds(
    rank_preds: &[ExprImpl],
    window_func_pos: usize,
) -> Option<(u64, u64)>
Expand description

Returns None if the conditions are too complex or invalid. Some((limit, offset)) otherwise.