Struct ColdReadStats 

pub struct ColdReadStats {
    pub cold_reads: AtomicU64,
}

Catalog: insertion-ordered Vec<Table> for stable iter / serialize, plus a BTreeMap<String, usize> sidecar index so get / get_mut run in O(log n) instead of the old linear scan with per-element string compares.

A pure BTreeMap<String, Table> was tried in an interim version of v3.1.2 and regressed the single-table catalog benches by ~10% (the per-element BTreeMap overhead outweighs the lookup win when n is small). The sidecar shape preserves the insertion-order iteration the on-disk encoding relies on and keeps last_mut (used by the deserialize hot path) cheap. v7.39 (pg_stat blks knife) — catalog-wide cold-tier read counter backing pg_stat_database.blks_read. Row-granular (SPG has no 8 KB page notion): one cold-segment row resolution = one “block read”, one hot row access = one “block hit” — the hit RATIO monitoring dashboards compute keeps its meaning. Volatile like PG’s stats.

Fields

cold_reads: AtomicU64

Trait Implementations

impl Clone for ColdReadStats

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColdReadStats

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

Formats the value using the given formatter.

impl Default for ColdReadStats

fn default() -> ColdReadStats

Returns the “default value” for a type.