September 2025 Monthly Summary (apache/calcite) Key focus: delivering API/metadata enhancements with targeted tests to improve function type introspection and reliability, while maintaining high code quality and test coverage. 1) Key features delivered - Exposed parameter types for FunctionSqlType via a new getter getParameterTypes() and associated tests. This enables accurate reflection of function signatures, improving tooling and runtime metadata access. - Change tied to CALCITE-7141 with commit [d22c8f31a7aaa1f2be0faa5b86300f838678ac12]: Add missing getter to FunctionSqlType. 2) Major bugs fixed - None reported for this period related to this work item. (Feature-focused update; no hotfixes recorded.) 3) Overall impact and accomplishments - Business value: Improved ability for clients and tooling to inspect function signatures, reducing guesswork and enabling safer dynamic usage of functions. - Technical accomplishments: API refinement (getter exposure), unit test coverage (FunctionSqlTypeTest) for constructor behavior, getters, and null/invalid parameter types handling, and null return type handling. - Maintained high quality with dedicated tests and alignment to CALCITE-7141. 4) Technologies/skills demonstrated - Java API design and refactoring (FunctionSqlType) - Unit testing with JUnit (FunctionSqlTypeTest) - Defensive programming and input validation (null/invalid parameter types handling) - Version control traceability (commit d22c8f31a7aaa1f2be0faa5b86300f838678ac12, CALCITE-7141)