Struct DeltaDataset 

pub struct DeltaDataset { /* private fields */ }

LSM-style delta dataset for a single edge type and direction.

Stores L1 sorted runs that accumulate edge mutations before compaction merges them into the base CSR.

Implementations

impl DeltaDataset

pub fn new(base_uri: &str, edge_type: &str, direction: &str) -> DeltaDataset

Create a new DeltaDataset rooted at base_uri for the given edge type and direction.

pub async fn open(&self) -> Result<Arc<Dataset>, Error>

Open the delta dataset at its latest version.

pub async fn open_at(&self, version: Option<u64>) -> Result<Arc<Dataset>, Error>

Open the delta dataset, optionally pinned to a specific Lance version.

pub fn get_arrow_schema(&self, schema: &Schema) -> Result<Arc<Schema>, Error>

Build the Arrow schema for this delta table using the given graph schema.

pub fn build_record_batch( &self, entries: &[L1Entry], schema: &Schema, ) -> Result<RecordBatch, Error>

Serialize entries into an Arrow RecordBatch using the given graph schema.

pub async fn scan_all(&self, schema: &Schema) -> Result<Vec<L1Entry>, Error>

Scan and return all L1 entries, sorted by direction key and version.

pub async fn scan_all_with_limit( &self, schema: &Schema, max_rows: usize, ) -> Result<Vec<L1Entry>, Error>

Scan all entries with a configurable row limit to prevent OOM.

pub async fn open_or_create( &self, backend: &(dyn StorageBackend + 'static), schema: &Schema, ) -> Result<(), Error>

Open or create a delta table via the storage backend.

pub async fn write_run( &self, backend: &(dyn StorageBackend + 'static), batch: RecordBatch, ) -> Result<(), Error>

Write a run to a delta table.

Creates the table if it doesn’t exist, otherwise appends to it.

pub async fn ensure_eid_index( &self, backend: &(dyn StorageBackend + 'static), ) -> Result<(), Error>

Ensure a BTree index exists on the ‘eid’ column.

pub fn table_name(&self) -> String

Get the table name for this delta dataset.

pub async fn scan_all_backend( &self, backend: &(dyn StorageBackend + 'static), schema: &Schema, ) -> Result<Vec<L1Entry>, Error>

Scan all entries from the backend table.

Returns an empty vector if the table doesn’t exist.

pub async fn scan_all_backend_with_limit( &self, backend: &(dyn StorageBackend + 'static), schema: &Schema, max_rows: usize, ) -> Result<Vec<L1Entry>, Error>

Scan all entries from the backend table with a configurable row limit to prevent OOM.

pub async fn replace( &self, backend: &(dyn StorageBackend + 'static), batch: RecordBatch, ) -> Result<(), Error>

Replace the delta table with a new batch (atomic replacement).

This is used during compaction to clear the delta table after merging into L2.

pub async fn read_deltas( &self, backend: &(dyn StorageBackend + 'static), vid: Vid, schema: &Schema, version_hwm: Option<u64>, ) -> Result<Vec<L1Entry>, Error>

Read delta entries for a specific vertex ID.

Returns an empty vector if the table doesn’t exist or no entries match.

pub async fn read_deltas_batch( &self, backend: &(dyn StorageBackend + 'static), vids: &[Vid], schema: &Schema, version_hwm: Option<u64>, ) -> Result<HashMap<Vid, Vec<L1Entry>>, Error>

Read delta entries for multiple vertex IDs in a single batch query.

Returns a HashMap mapping each vid to its delta entries. VIDs with no delta entries will not be in the map.

Trait Implementations

impl Debug for DeltaDataset

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

Formats the value using the given formatter.