risingwave_frontend::optimizer::plan_visitor::cardinality_visitor

Trait LogicalCardinalityExt

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

Required Methods§

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fn max_one_row(&self) -> bool

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

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

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

Implementors§