Struct DataChunk 

pub struct DataChunk { /* private fields */ }

A batch of rows stored column-wise for vectorized processing.

Instead of storing rows like [(a1,b1), (a2,b2), ...], we store columns like [a1,a2,...], [b1,b2,...]. This is cache-friendly for analytical queries that touch few columns but many rows.

The optional SelectionVector lets you filter rows without copying data - just mark which row indices are “selected”.

Example

use grafeo_core::execution::DataChunk;
use grafeo_core::execution::ValueVector;
use grafeo_common::types::Value;

// Create columns
let names = ValueVector::from_values(&[Value::from("Alix"), Value::from("Gus")]);
let ages = ValueVector::from_values(&[Value::from(30i64), Value::from(25i64)]);

// Bundle into a chunk
let chunk = DataChunk::new(vec![names, ages]);
assert_eq!(chunk.len(), 2);

Implementations

impl DataChunk

pub fn empty() -> Self

Creates an empty data chunk with no columns.

pub fn new(columns: Vec<ValueVector>) -> Self

Creates a new data chunk from existing vectors.

pub fn with_schema(column_types: &[LogicalType]) -> Self

Creates a new empty data chunk with the given schema.

pub fn with_capacity(column_types: &[LogicalType], capacity: usize) -> Self

Creates a new data chunk with the given schema and capacity.

pub fn column_count(&self) -> usize

Returns the number of columns.

pub fn row_count(&self) -> usize

Returns the number of rows (considering selection).

pub fn len(&self) -> usize

Alias for row_count().

pub fn columns(&self) -> &[ValueVector]

Returns all columns.

pub fn total_row_count(&self) -> usize

Returns the total number of rows (ignoring selection).

pub fn is_empty(&self) -> bool

Returns true if the chunk is empty.

pub fn capacity(&self) -> usize

Returns the capacity of this chunk.

pub fn is_full(&self) -> bool

Returns true if the chunk is full.

pub fn column(&self, index: usize) -> Option<&ValueVector>

Gets a column by index.

pub fn column_mut(&mut self, index: usize) -> Option<&mut ValueVector>

Gets a mutable column by index.

pub fn selection(&self) -> Option<&SelectionVector>

Returns the selection vector.

pub fn set_selection(&mut self, selection: SelectionVector)

Sets the selection vector.

pub fn clear_selection(&mut self)

Clears the selection vector (selects all rows).

pub fn set_zone_hints(&mut self, hints: ChunkZoneHints)

Sets zone map hints for this chunk.

Zone map hints enable the filter operator to skip entire chunks when predicates can’t possibly match based on min/max statistics.

pub fn zone_hints(&self) -> Option<&ChunkZoneHints>

Returns zone map hints if available.

Used by the filter operator for chunk-level predicate pruning.

pub fn clear_zone_hints(&mut self)

Clears zone map hints.

pub fn set_count(&mut self, count: usize)

Sets the row count.

pub fn reset(&mut self)

Resets the chunk for reuse.

pub fn flatten(&mut self)

Flattens the selection by copying only selected rows.

After this operation, selection is None and count equals the previously selected row count.

pub fn sort_by_column(&self, col_idx: usize) -> DataChunk

Returns a new chunk with rows sorted by the values in the given column.

For NodeId columns, sorts by the raw node ID. For other types, sorts by the Value’s natural ordering. Rows with null values in the sort column are placed last.

This is used for locality optimization: sorting by source node ID before an expand operator groups nearby nodes together, improving cache locality during adjacency index lookups.

pub fn selected_indices(&self) -> Box<dyn Iterator<Item = usize> + '_>

Returns an iterator over selected row indices.

pub fn concat(chunks: &[DataChunk]) -> DataChunk

Concatenates multiple chunks into a single chunk.

All chunks must have the same schema (same number and types of columns).

pub fn filter(&self, predicate: &SelectionVector) -> DataChunk

Applies a filter predicate and returns a new chunk with selected rows.

pub fn slice(&self, offset: usize, count: usize) -> DataChunk

Returns a slice of this chunk.

Returns a new DataChunk containing rows [offset, offset + count).

pub fn num_columns(&self) -> usize

Returns the number of columns.

Trait Implementations

impl Clone for DataChunk

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 DataChunk

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

Formats the value using the given formatter.

impl From<DataChunk> for ChunkVariant

fn from(chunk: DataChunk) -> Self

Converts to this type from the input type.