Struct ZoneMap

pub struct ZoneMap { /* private fields */ }

A zone map containing statistics for a column. Each row of the zone map corresponds to a chunk of the column.

Note that it’s possible for the zone map to have no statistics.

Implementations

impl ZoneMap

pub fn try_new( column_dtype: DType, array: StructArray, stats: Arc<[Stat]>, ) -> VortexResult<Self>

Create ZoneMap of given column_dtype from given array. Validates that the array matches expected structure for given list of stats.

pub fn new_unchecked(array: StructArray, stats: Arc<[Stat]>) -> Self

Creates ZoneMap without validating return array against expected stats.

pub fn dtype_for_stats_table( column_dtype: &DType, present_stats: &[Stat], ) -> DType

Returns the DType of the statistics table given a set of statistics and column DType.

pub fn array(&self) -> &StructArray

Returns the underlying StructArray backing the zone map

pub fn present_stats(&self) -> &Arc<[Stat]>

Returns the list of stats included in the zone map.

pub fn to_stats_set(&self, stats: &[Stat]) -> VortexResult<StatsSet>

Returns an aggregated stats set for the table.

pub fn get_stat(&self, stat: Stat) -> VortexResult<Option<ArrayRef>>

Returns the array for a given stat.

pub fn prune(&self, predicate: &ExprRef) -> VortexResult<Mask>

Apply a pruning predicate against the ZoneMap, yielding a mask indicating which zones can be pruned.

The expression provided should be the result of converting an existing VortexExpr via checked_pruning_expr into a prunable expression that can be evaluated on a zone map.

All zones where the predicate evaluates to true can be skipped entirely.

Trait Implementations

impl Clone for ZoneMap

fn clone(&self) -> ZoneMap

Returns a duplicate of the value.

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

Performs copy-assignment from source.