Module delta 

Delta Lake sink connector implementation.

DeltaLakeSink implements SinkConnector, writing Arrow RecordBatch data to Delta Lake tables with ACID transactions and at-least-once delivery (exactly-once opt-in via delivery.guarantee = 'exactly-once').

Write Strategies

• Append mode: Arrow-to-Parquet zero-copy writes for immutable streams
• Overwrite mode: Replace partition contents for recomputation
• Upsert mode: CDC MERGE via Z-set changelog integration

Exactly-once semantics use epoch-to-Delta-version mapping: each LaminarDB epoch maps to exactly one Delta Lake transaction via txn application transaction metadata in the Delta log.

Ring Architecture

• Ring 0: No sink code. Data arrives via SPSC channel (~5ns push).
• Ring 1: Batch buffering, Parquet writes, Delta log commits.
• Ring 2: Schema management, configuration, health checks.

Structs

DeltaLakeSink

Delta Lake sink connector.