March 2026 monthly summary focusing on delivered features and code quality improvements for the apache/iceberg repository. Key effort was dedicated to refining the test suite by removing unnecessary table refresh calls, resulting in faster and more maintainable tests. Committed changes demonstrate cross-Spark version compatibility and a commitment to test suite robustness.

November 2025 monthly summary for apache/iceberg. Focused on precision in specification documentation to support stable downstream integration and alignment with current format version and geography type definitions. No major feature work completed this month; however, a critical spec correction was implemented to reduce ambiguity and maintain compatibility with existing users and downstream components.

June 2025: Key feature deliveries in apache/iceberg focused on maintainability and Spark 4.0 integration. No major bugs fixed this month. Highlights include an internal refactor that introduces CommonReader and a ReaderFunction interface to unify VectorizedParquetDefinitionLevelReader behavior across data batches, and the addition of MERGE INTO support via the DataFrame API for Spark 4.0, supported by documentation and tests. Impact: reduces code duplication, simplifies future enhancements, and accelerates adoption of MERGE INTO through Spark's DataFrame API. Technologies: Java/Arrow codebase, abstraction design (CommonReader, ReaderFunction), DataFrame API, Spark 4.0, unit/integration testing, and documentation.

May 2025: Implemented Structured Streaming ReadLimit enhancements in Apache Iceberg to enable precise control of reads in Spark Structured Streaming, improving throughput predictability and reliability for long-running streaming jobs. Key work included refactoring SparkMicroBatchStream to parse/apply ReadMaxFiles and ReadMaxRows, backporting read-limit support across Spark versions 3.4–4.0, and expanding tests to cover composite limits. Also clarified v3 metadata source-ids usage in docs (no code changes) and fixed a streaming read bug to skip rewrite snapshots, ensuring data correctness. Overall, these changes reduce operational risk, improve resource planning for large streaming workloads, and strengthen end-to-end streaming reliability.

March 2025: Focused on reliability and accuracy of Spark statistics reporting in Apache Iceberg. Delivered a targeted bug fix for SparkScan: the statistics file now matches the current snapshot ID when estimating statistics, by iterating through available files rather than defaulting to the first one. This improves accuracy of statistics reported for Spark scans and reduces discrepancies in Spark workloads analytics.

November 2024: Delivered a targeted Parquet reader enhancement in rapid7/iceberg that uses PageReadStore.getRowIndexOffset to determine the starting row for each row group, replacing manual calculations. This refactor simplifies the Parquet reader, reduces potential off-by-one errors, and lays groundwork for performance improvements in the read path.