Struct ColumnarProjection 

pub struct ColumnarProjection { /* private fields */ }

The columnar analytics projection for one append-only collection.

Implementations

impl ColumnarProjection

pub fn new(schema: ProjectionSchema, key: [u8; 32]) -> Self

Create a projection over schema, sealing segments under key.

pub fn manifest(&self) -> &ProjectionManifest

pub fn drop_projection(&mut self)

Drop every materialized segment. Repair is always “regenerate”: after a drop, the next emit_at_checkpoint rebuilds the projection from the row log, and reads keep working meanwhile (served entirely by the row tail).

pub fn rebuild_from_truth( &mut self, collection: &AppendOnlyCollection, checkpoint_lsn: u64, budget: TranscodeBudget, ) -> Result<EmitOutcome, ProjectionError>

Rebuild the derived projection from the row log. This is the repair primitive for missing or corrupt projection artifacts: truth stays in AppendOnlyCollection, so repair is drop-and-regenerate.

pub fn emit_at_checkpoint( &mut self, collection: &AppendOnlyCollection, checkpoint_lsn: u64, budget: TranscodeBudget, ) -> Result<EmitOutcome, ProjectionError>

Emit columnar segments for the un-materialized tail up to checkpoint_lsn, bounded by budget. Never fails for lack of budget: it transcodes a prefix and defers the rest. This is the only producer of columnar segments (ADR 0069 §2).

pub fn analytical_scan( &self, collection: &AppendOnlyCollection, pinned_lsn: u64, ) -> Result<Vec<Row>, ProjectionError>

The LSN-pinned analytical scan (ADR 0069 §4). Under a single pinned LSN: decode columnar segments up to the last materialized LSN, then concatenate the un-materialized tail through the row read path. The result is identical, row-for-row and in order, to AppendOnlyCollection::row_scan at the same pinned_lsn — one consistency class, always fresh; AS OF is just a historical pin.

pub fn repairing_analytical_scan( &mut self, collection: &AppendOnlyCollection, pinned_lsn: u64, budget: TranscodeBudget, ) -> Result<Vec<Row>, ProjectionError>

Analytical scan with projection repair. Missing derived segment bytes or checksum/envelope/frame failures never make the query depend on a bad projection: the projection is dropped, rebuilt from the row log, and scanned again under the same LSN pin.

Trait Implementations

impl Clone for ColumnarProjection

fn clone(&self) -> ColumnarProjection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnarProjection

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

Formats the value using the given formatter.