Struct StaticCostModel

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pub struct StaticCostModel;

Expand description

Static, row-count-aware cost model for logical plans.

Walks every node in the plan and accumulates cost estimates based on operator type and the node’s estimated_rows field. When estimated_rows is None a conservative default of 10 000 rows is assumed.

§Per-node coefficients

Operator	CPU (ns/row)	Memory (B/row)	Network (B/row)
Scan	10	64	0
Filter	5	0	0
Project	2	0	0
Aggregate	50	200	0
Join	100	100	0
Exchange	20	0	200
Other/Window	15	64	0

These figures are deliberately simple and tunable; their absolute values are less important than their relative ordering (Aggregate > Join > …).

Trait Implementations§

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impl CostModel for StaticCostModel

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fn estimate(&self, plan: &LogicalPlan) -> Cost

Return an estimated Cost for the given logical plan.

Auto Trait Implementations§

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impl UnwindSafe for StaticCostModel

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