Struct ColumnarEngine 

pub struct ColumnarEngine<S: StorageEngine> { /* private fields */ }

Manages all columnar collections for a NodeDbLite instance.

Implementations

impl<S: StorageEngine> ColumnarEngine<S>

pub fn new(storage: Arc<S>) -> Self

Create a new empty columnar engine.

pub async fn restore(storage: Arc<S>) -> Result<Self, LiteError>

Restore columnar collections from storage on startup.

pub async fn create_collection( &mut self, name: &str, schema: ColumnarSchema, profile: ColumnarProfile, ) -> Result<(), LiteError>

Create a new columnar collection.

pub async fn drop_collection(&mut self, name: &str) -> Result<(), LiteError>

Drop a columnar collection and all its data.

pub async fn alter_add_column( &mut self, name: &str, column: ColumnDef, ) -> Result<(), LiteError>

Add a column to an existing columnar collection.

Bumps the schema version. Existing segments are NOT rewritten — the reader null-fills columns that were added after the segment was written.

pub fn schema(&self, name: &str) -> Option<&ColumnarSchema>

Get the schema for a collection.

pub fn profile(&self, name: &str) -> Option<&ColumnarProfile>

Get the profile for a collection.

pub fn collection_names(&self) -> Vec<&str>

List all columnar collection names.

pub fn insert( &mut self, collection: &str, values: &[Value], ) -> Result<(), LiteError>

Insert a row into a columnar collection’s memtable.

pub fn delete( &mut self, collection: &str, pk: &Value, ) -> Result<bool, LiteError>

Delete a row by PK.

Rejects deletion on timeseries collections (append-only constraint). Marks the row in the segment’s delete bitmap. Compaction is triggered separately via try_compact_collection when the delete ratio exceeds 20%.

pub fn update( &mut self, collection: &str, old_pk: &Value, new_values: &[Value], ) -> Result<bool, LiteError>

Update a row: DELETE old + INSERT new.

Rejects update on timeseries collections (append-only constraint).

pub async fn flush_collection( &mut self, collection: &str, ) -> Result<(), LiteError>

Flush the memtable for a collection to a new segment.

Called when the memtable reaches its threshold or on shutdown.

pub async fn flush_all(&mut self) -> Result<(), LiteError>

Flush all collections’ memtables.

pub async fn try_compact_collection( &mut self, collection: &str, ) -> Result<bool, LiteError>

Check if any segments need compaction and run it.

Compaction is triggered when a segment’s delete ratio exceeds 20%. The old segment is replaced with a compacted one (deleted rows removed).

pub async fn read_segments( &self, collection: &str, ) -> Result<Vec<(u32, Vec<u8>)>, LiteError>

Read all segment bytes for a collection (for the table provider).

pub fn delete_bitmap( &self, collection: &str, segment_id: u32, ) -> Option<&DeleteBitmap>

Get the delete bitmap for a segment.

pub fn row_count(&self, collection: &str) -> usize

Row count across all segments + memtable for a collection.