Struct PlanKey 

pub struct PlanKey {
    pub query_hash: u64,
    pub schema_version: u64,
    pub collection_generations: SmallVec<[u64; 4]>,
}

Deterministic cache key for compiled query plans.

Two keys are equal iff the query text is identical AND the database state (schema version + per-collection write generations) has not changed.

collection_generations must be sorted by collection name before insertion for deterministic hashing.

Correctness invariant (CACHE-01)

Cache correctness depends on query_hash capturing all collection names referenced by the query (base table + JOIN targets). If two structurally different queries happened to hash to the same value the cache would serve a stale plan. This is prevented by using the full canonical serialization of the Query AST — not just the collection name — as the hash input (see Database::build_plan_key). The collection_generations vector is then ordered by collection name so that the same set of collections always produces the same key regardless of JOIN ordering.

Fields

query_hash: u64

FxHash of canonical query text.

schema_version: u64

Monotonic counter incremented on every DDL operation.

collection_generations: SmallVec<[u64; 4]>

Per-collection write generation, sorted by collection name.

Trait Implementations

impl Clone for PlanKey

fn clone(&self) -> PlanKey

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PlanKey

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

Formats the value using the given formatter.

impl Hash for PlanKey

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 PlanKey

fn eq(&self, other: &PlanKey) -> 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 Eq for PlanKey

impl StructuralPartialEq for PlanKey