Struct ColumnarDelta 

pub struct ColumnarDelta { /* private fields */ }

Columnar Delta Store with MVCC support.

Stores versioned RecordBatches for each table, enabling:

• Snapshot Isolation via VersionedBatch
• Efficient columnar scans via Arrow
• Memory sharing via Arc<RecordBatch>

Implementations

impl ColumnarDelta

pub fn new(flush_threshold: usize) -> Self

Create a new ColumnarDelta with the given flush threshold.

pub fn insert_versioned_batch( &self, table: &str, batch: RecordBatch, begin_ts: u64, ) -> DbxResult<()>

Insert a versioned batch for a table.

The batch will be assigned a sequence number and begin_ts.

pub fn get_visible_batches( &self, table: &str, read_ts: u64, ) -> Vec<Arc<RecordBatch>>

Get all batches visible to a snapshot at the given read_ts.

pub fn should_flush(&self) -> bool

Check if flush is needed based on row count threshold.

pub fn row_count(&self) -> usize

Get the current row count across all tables.

pub fn drain_table(&self, table: &str) -> Vec<VersionedBatch>

Drain all batches from a table (for flushing to WOS/Parquet).

Returns all batches and clears the table.

pub fn table_names(&self) -> Vec<String>

Get all table names.

Trait Implementations

impl StorageBackend for ColumnarDelta

fn insert(&self, table: &str, key: &[u8], value: &[u8]) -> DbxResult<()>

Insert a key-value pair.

fn insert_batch( &self, table: &str, rows: Vec<(Vec<u8>, Vec<u8>)>, ) -> DbxResult<()>

Insert multiple key-value pairs in a batch (optimized).

fn get(&self, table: &str, key: &[u8]) -> DbxResult<Option<Vec<u8>>>

Get a value by key.

fn delete(&self, table: &str, key: &[u8]) -> DbxResult<bool>

Delete a key-value pair.

fn scan<R: RangeBounds<Vec<u8>> + Clone>( &self, table: &str, range: R, ) -> DbxResult<Vec<(Vec<u8>, Vec<u8>)>>

Scan a range of keys.

fn scan_one<R: RangeBounds<Vec<u8>> + Clone>( &self, table: &str, range: R, ) -> DbxResult<Option<(Vec<u8>, Vec<u8>)>>

Scan a single key-value pair in a range (optimized).

fn flush(&self) -> DbxResult<()>

Flush any buffered data to durable storage.

fn count(&self, table: &str) -> DbxResult<usize>

Return the number of keys in the given table.

fn table_names(&self) -> DbxResult<Vec<String>>

Return all table names managed by this backend.