Struct Cost 

pub struct Cost {
    pub cpu: f64,
    pub io: f64,
    pub memory: f64,
    pub network: f64,
}

Cost of an operation.

Represents the estimated resource consumption of executing an operator.

Fields

cpu: f64

Estimated CPU cycles / work units.

io: f64

Estimated I/O operations (page reads).

memory: f64

Estimated memory usage in bytes.

network: f64

Network cost (for distributed queries).

Implementations

impl Cost

pub fn zero() -> Self

Creates a zero cost.

pub fn cpu(cpu: f64) -> Self

Creates a cost from CPU work units.

pub fn with_io(self, io: f64) -> Self

Adds I/O cost.

pub fn with_memory(self, memory: f64) -> Self

Adds memory cost.

pub fn total(&self) -> f64

Returns the total weighted cost.

Uses default weights: CPU=1.0, IO=10.0, Memory=0.1, Network=100.0

pub fn total_weighted( &self, cpu_weight: f64, io_weight: f64, mem_weight: f64, ) -> f64

Returns the total cost with custom weights.

Trait Implementations

impl Add for Cost

type Output = Cost

The resulting type after applying the + operator.

fn add(self, other: Self) -> Self

Performs the + operation.

impl AddAssign for Cost

fn add_assign(&mut self, other: Self)

Performs the += operation.

impl Clone for Cost

fn clone(&self) -> Cost

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Cost

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Cost

fn eq(&self, other: &Cost) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Cost

impl StructuralPartialEq for Cost