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, num_row_groups: 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.

Skip the row group if the row count is 0.

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 contains_non_empty_row_group(&self, row_group_id: usize) -> bool

Returns true if the selection contains a row group with the given ID and the row selection is not empty.

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.

pub fn concat(&mut self, other: &Self)

Concatenates other into self. other must not contain row groups that self contains.

Panics if self contains row groups that other contains.

fn fill_missing_row_groups( selection_in_rg: &mut BTreeMap<usize, RowSelectionWithCount>, num_row_groups: usize, )

Fills the missing row groups with empty selections. This is to indicate that the row groups are searched even if no rows are found.

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.