Struct RowGroupSelection

pub struct RowGroupSelection {
    selection_in_rg: BTreeMap<usize, RowSelectionWithCount>,
    row_count: usize,
    selector_len: usize,
}

A selection of row groups.

Fields

selection_in_rg: BTreeMap<usize, RowSelectionWithCount>

Row group id to row selection.

row_count: usize

Total number of rows in the selection.

selector_len: usize

Total length of the selectors.

Implementations

impl RowGroupSelection

pub fn new(row_group_size: usize, total_row_count: usize) -> Self

Creates a new RowGroupSelection with all row groups selected.

Arguments

• row_group_size - The number of rows in each row group (except possibly the last one)
• total_row_count - Total number of rows

pub fn get(&self, rg_id: usize) -> Option<&RowSelection>

Returns the row selection for a given row group.

None indicates not selected.

pub fn from_inverted_index_apply_output( row_group_size: usize, apply_output: ApplyOutput, ) -> Self

Creates a new RowGroupSelection from the output of inverted index application.

Arguments

• row_group_size - The number of rows in each row group (except possibly the last one)
• apply_output - The output from applying the inverted index

Assumptions

• All row groups (except possibly the last one) have the same number of rows
• The last row group may have fewer rows than row_group_size

pub fn from_row_ids( row_ids: BTreeSet<u32>, row_group_size: usize, num_row_groups: usize, ) -> Self

Creates a new RowGroupSelection from a set of row IDs.

Arguments

• row_ids - Set of row IDs to select
• row_group_size - The number of rows in each row group (except possibly the last one)
• num_row_groups - Total number of row groups

Assumptions

• All row groups (except possibly the last one) have the same number of rows
• The last row group may have fewer rows than row_group_size
• All row IDs must within the range of [0, num_row_groups * row_group_size)

pub fn from_row_ranges( row_ranges: Vec<(usize, Vec<Range<usize>>)>, row_group_size: usize, ) -> Self

Creates a new RowGroupSelection from a set of row ranges.

Arguments

• row_ranges - A vector of (row_group_id, row_ranges) pairs
• row_group_size - The number of rows in each row group (except possibly the last one)

Assumptions

• All row groups (except possibly the last one) have the same number of rows
• The last row group may have fewer rows than row_group_size
• All ranges in row_ranges must be within the bounds of their respective row groups (i.e., for row group i, all ranges must be within [0, row_group_size) or [0, remaining_rows) for the last row group)
• Ranges within the same row group must not overlap. Overlapping ranges will result in undefined behavior.

fn group_row_ids_by_row_group( row_ids: BTreeSet<u32>, row_group_size: usize, num_row_groups: usize, ) -> Vec<(usize, Vec<usize>)>

Groups row IDs by their row group.

Arguments

• row_ids - Set of row IDs to group
• row_group_size - Size of each row group
• num_row_groups - Total number of row groups

Returns

A vector of (row_group_id, row_ids) pairs, where row_ids are the IDs within that row group.

pub fn intersect(&self, other: &Self) -> Self

Intersects two RowGroupSelections.

pub fn row_group_count(&self) -> usize

Returns the number of row groups in the selection.

pub fn row_count(&self) -> usize

Returns the number of rows in the selection.

pub fn pop_first(&mut self) -> Option<(usize, RowSelection)>

Returns the first row group in the selection.

pub fn remove_row_group(&mut self, row_group_id: usize)

Removes a row group from the selection.

pub fn is_empty(&self) -> bool

Returns true if the selection is empty.

pub fn contains_row_group(&self, row_group_id: usize) -> bool

Returns true if the selection contains a row group with the given ID.

pub fn iter(&self) -> impl Iterator<Item = (&usize, &RowSelection)>

Returns an iterator over the row groups in the selection.

pub fn mem_usage(&self) -> usize

Returns the memory usage of the selection.

Trait Implementations

impl Clone for RowGroupSelection

fn clone(&self) -> RowGroupSelection

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RowGroupSelection

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

Formats the value using the given formatter.

impl Default for RowGroupSelection

fn default() -> RowGroupSelection

Returns the “default value” for a type.