Struct ExternalSort 

pub struct ExternalSort { /* private fields */ }

External merge sort for out-of-core sorting.

Manages sorted runs on disk and provides k-way merge.

Implementations

impl ExternalSort

pub fn new( manager: Arc<SpillManager>, num_columns: usize, sort_keys: Vec<SortKey>, ) -> Self

Creates a new external sort.

pub fn num_runs(&self) -> usize

Returns the number of runs on disk.

pub fn total_rows(&self) -> usize

Returns the total number of rows across all runs.

pub fn spill_sorted_run(&mut self, rows: Vec<Vec<Value>>) -> Result<()>

Spills an already-sorted buffer as a run to disk.

The buffer must already be sorted according to the sort keys.

Errors

Returns an error if writing to disk fails.

pub fn merge_all( &mut self, in_memory_buffer: Vec<Vec<Value>>, ) -> Result<Vec<Vec<Value>>>

Merges all runs and an optional in-memory buffer into sorted output.

Uses k-way merge with a min-heap.

Errors

Returns an error if reading from disk fails.

pub fn cleanup(&mut self)

Cleans up all spill files.

Trait Implementations

impl Drop for ExternalSort

fn drop(&mut self)

Executes the destructor for this type.