Struct LogicalPlanSignature 

pub struct LogicalPlanSignature {
    node_number: NonZeroUsize,
    plan_hash: u64,
}

Non-unique identifier of a LogicalPlan.

See LogicalPlanSignature::new for details.

Fields

node_number: NonZeroUsize

plan_hash: u64

Implementations

impl LogicalPlanSignature

pub fn new(plan: &LogicalPlan) -> Self

Returns LogicalPlanSignature of the given LogicalPlan.

It is a kind of LogicalPlan hashing with stronger guarantees.

Guarantees

Consider two LogicalPlans p1 and p2.

If p1 and p2 have a different number of LogicalPlans, then they will have different LogicalPlanSignatures.

If p1 and p2 have a different Hash, then they will have different LogicalPlanSignatures.

Caveats

The intention of LogicalPlanSignature is to have a lower chance of hash collisions.

There exist different LogicalPlans with the same LogicalPlanSignature.

When two LogicalPlans differ only in metadata, then they will have the same LogicalPlanSignatures (due to hash implementation in LogicalPlan).

Trait Implementations

impl Clone for LogicalPlanSignature

fn clone(&self) -> LogicalPlanSignature

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Hash for LogicalPlanSignature

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for LogicalPlanSignature

fn eq(&self, other: &LogicalPlanSignature) -> 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 LogicalPlanSignature

impl Eq for LogicalPlanSignature

impl StructuralPartialEq for LogicalPlanSignature