Struct QueryStats 

pub struct QueryStats {
    pub version: u32,
    pub families: BTreeMap<IndexFamily, FamilyStats>,
    pub total_observations: u64,
}

Aggregated statistics across all index families.

version is bumped when the on-disk layout changes; loaders refuse to read incompatible versions.

Fields

version: u32

Storage format version.

families: BTreeMap<IndexFamily, FamilyStats>

Per-family running aggregates.

total_observations: u64

Total number of observations recorded since creation.

Implementations

impl QueryStats

pub const CURRENT_VERSION: u32 = 1

On-disk format version this build emits.

pub fn new() -> Self

Construct an empty stats container.

pub fn family_stats(&self, family: IndexFamily) -> &FamilyStats

Borrow stats for a specific family (always present after default()).

pub fn record(&mut self, obs: QueryObservation)

Record a new observation, updating running aggregates.

pub fn recommended_weights(&self, prior: &CostWeights) -> CostWeights

Recommend cost-model weights from accumulated observations.

The weight for a family is set to mean_observed_latency_us / mean_predicted_cost, capped to the safe range enforced by CostWeights::set. Families with no observations keep their previous weights.

Pass the current weights as prior so untouched families retain their existing values.

pub fn save<P: AsRef<Path>>(&self, path: P) -> Result<()>

Serialise to a JSON file, atomically replacing any existing copy.

pub fn load<P: AsRef<Path>>(path: P) -> Result<Self>

Load from a JSON file. Refuses to read versions newer than this build.

Trait Implementations

impl Clone for QueryStats

fn clone(&self) -> QueryStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryStats

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

Formats the value using the given formatter.

impl Default for QueryStats

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for QueryStats

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for QueryStats

fn eq(&self, other: &QueryStats) -> 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 Serialize for QueryStats

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for QueryStats