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]>, zone_len: u64, row_count: u64, ) -> VortexResult<Self>

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

pub unsafe fn new_unchecked( array: StructArray, zone_len: u64, row_count: u64, ) -> Self

Creates ZoneMap without validating return array against expected stats.

Safety

Assumes that the input struct array has the correct statistics as fields. Or in other words,

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

👎Deprecated:

use stats_table_dtype from crate::layouts::zoned::schema instead

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

This remains as a compatibility wrapper around the zoned schema helper.

pub fn prune( &self, predicate: &Expression, session: &VortexSession, ) -> VortexResult<Mask>

Apply a pruning predicate to this zone map.

predicate should be the result of converting a filter with checked_pruning_expr. The returned mask has one value per zone, where true means the zone cannot contain matching rows and can be skipped.

If the predicate contains row_count placeholders, they are replaced after ArrayRef::apply with per-zone counts derived from zone_len and row_count. Uniform zones use a ConstantArray; a short final zone uses a run-end encoded array.

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.