Struct ZoneMap 

pub struct ZoneMap { /* private fields */ }

Reusable per-block zone map.

Implementations

impl ZoneMap

pub fn with_capacity(expected_rows: usize) -> ZoneMap

Create a zone map sized for expected_rows. The bloom is tuned to the row estimate; HLL is fixed-size (~16 KB).

pub fn new() -> ZoneMap

Default: sized for 4 KB table pages (~128 rows).

pub fn observe(&mut self, key: &[u8])

Record a non-null value observation.

pub fn observe_null(&mut self)

Record a null observation. Does not touch the bloom / HLL since there is no key to hash.

pub fn min(&self) -> Option<&[u8]>

Minimum observed key, if any.

pub fn max(&self) -> Option<&[u8]>

Maximum observed key, if any.

pub fn total_count(&self) -> u64

Total rows observed (including nulls).

pub fn null_count(&self) -> u64

Rows observed as null.

pub fn non_null_count(&self) -> u64

Rows observed as non-null.

pub fn distinct_estimate(&self) -> u64

Estimated distinct non-null values.

pub fn bloom(&self) -> &BloomSegment

Access the underlying bloom (for cross-structure helpers).

pub fn block_skip(&self, predicate: &ZonePredicate<'_>) -> ZoneDecision

Decide whether to skip a block given a predicate.

Safe by default: when uncertain, returns ZoneDecision::MustRead.

pub fn union(&mut self, other: &ZoneMap)

Merge another zone map into this one (e.g. aggregating block-level maps into a segment-level summary).

pub fn clear(&mut self)

Reset to the empty state.

Trait Implementations

impl Default for ZoneMap

fn default() -> ZoneMap

Returns the “default value” for a type.

impl HasBloom for ZoneMap

fn bloom_segment(&self) -> Option<&BloomSegment>

Reference to the bloom filter attached to this segment, if any.

fn definitely_absent(&self, key: &[u8]) -> bool

Fast-path negative check. Returns true iff the bloom is present and reports the key as absent.

impl IndexBase for ZoneMap

fn name(&self) -> &str

Human-readable name (e.g. “users.email”, “graph.city_by_node”).

fn kind(&self) -> IndexKind

Index family (btree, hash, bitmap, hnsw, …).

fn stats(&self) -> IndexStats

Current statistics (cardinality, estimated selectivity, memory).

fn bloom(&self) -> Option<&BloomFilter>

Optional bloom filter for fast negative lookups. Cross-structure pruning relies on this.

fn definitely_absent(&self, key_bytes: &[u8]) -> bool

Returns true iff the key is guaranteed to be absent from this index. Default implementation consults IndexBase::bloom and falls back to false when no bloom is available (meaning “don’t know — caller must probe”).