Enum VectorMetric 

pub enum VectorMetric {
    L2,
    Cosine,
    InnerProduct,
}

Distance metric for a Vector(n) similarity search (see docs/design/extensions.md §6/§7, cratestack#163). Maps 1:1 onto pgvector’s three distance operators and the opclass names used by @@index([...], opclass: "...") (cratestack#156’s DDL) — but is never inferred from an index: an index is only ever an optional access-path speedup, and AC #2 on cratestack#163 requires distance ordering/filtering to keep working with no vector index present at all (a plain sequential scan), so callers state the metric explicitly at the call site. VectorMetric::from_opclass is a convenience for callers that already know their index’s opclass and don’t want to duplicate the mapping by hand — it is never called automatically.

Variants

L2

Euclidean (L2) distance — operator <->, opclass vector_l2_ops.

Cosine

Cosine distance — operator <=>, opclass vector_cosine_ops.

InnerProduct

Negative inner product — operator <#>, opclass vector_ip_ops.

Implementations

impl VectorMetric

pub const fn sql_operator(self) -> &'static str

The Postgres operator pgvector registers for this metric.

pub fn from_opclass(opclass: &str) -> Option<VectorMetric>

Map a pgvector opclass string, as used in @@index([...], opclass: "vector_l2_ops") (cratestack#156), to the metric it indexes. Returns None for anything that isn’t one of pgvector’s three recognized vector opclasses (including a non-vector opclass on an unrelated index).

Trait Implementations

impl Clone for VectorMetric

fn clone(&self) -> VectorMetric

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for VectorMetric

impl Debug for VectorMetric

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

Formats the value using the given formatter.

impl Eq for VectorMetric

impl PartialEq for VectorMetric

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for VectorMetric