grafeo_engine::query::optimizer::cardinality

Struct CardinalityEstimator

pub struct CardinalityEstimator { /* private fields */ }

Expand description

Cardinality estimator.

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impl CardinalityEstimator

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pub fn new() -> Self

Creates a new cardinality estimator with default settings.

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pub fn from_statistics(stats: &Statistics) -> Self

Creates a cardinality estimator pre-populated from store statistics.

Maps LabelStatistics to TableStats and computes the average edge fanout from EdgeTypeStatistics. Falls back to defaults for any missing statistics.

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pub fn add_table_stats(&mut self, name: &str, stats: TableStats)

Adds statistics for a table/label.

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pub fn set_avg_fanout(&mut self, fanout: f64)

Sets the average edge fanout.

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pub fn estimate(&self, op: &LogicalOperator) -> f64

Estimates the cardinality of a logical operator.

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impl Default for CardinalityEstimator

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fn default() -> Self

Returns the “default value” for a type. Read more

Auto Trait Implementations§

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impl UnwindSafe for CardinalityEstimator

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

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impl<T, U> Into for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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