Month: 2026-06 — Key features delivered: Stability improvement in data lineage tracking for recursive CTEs with column aliases, ensuring the analysis maintains accurate source column information. Major bugs fixed: Corrected incorrect column lineage for recursive CTEs with column aliases (commit 3c7bbe1e526dc6696acc55220e621c40f9431710). Overall impact and accomplishments: Enhances reliability of lineage-based query impact analysis for complex queries, reducing debugging time and risk in data provenance reporting. Technologies and skills demonstrated: SQL lineage analysis, recursive CTE reasoning, rigorous debugging, and Git-based change management in trinodb/trino.

June 2025 — Focused on correctness in case-insensitive join semantics for common column matching. Delivered a critical bug fix in apache/calcite that ensures NATURAL JOIN and JOIN USING align column matches correctly when caseSensitive is disabled, with comprehensive tests validating various casing scenarios. This work reduces erroneous query results and increases reliability in cross-database workflows. Technologies demonstrated: Java, Calcite internals, test-driven development, and regression test coverage.