risingwave_frontend::optimizer::plan_visitor::cardinality_visitor

Trait LogicalCardinalityExt

Source 
pub trait LogicalCardinalityExt {
    // Required methods
    fn max_one_row(&self) -> bool;
    fn row_count(&self) -> Option<usize>;
}

Required Methods§

Source

fn max_one_row(&self) -> bool

Returns true if the plan node is guaranteed to yield at most one row.

Source

fn row_count(&self) -> Option<usize>

Returns the number of rows the plan node is guaranteed to yield, if known exactly.

Implementors§