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 is selected once at the pipeline/runtime boundary).

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 append writes prepare immutable Parquet descriptors during the checkpoint and publish them with one namespaced, designated Delta commit. At-least-once append, overwrite, and upsert writes commit through flush().

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.