Worked on the apache/phoenix repository to address a reliability issue in SQL parsing related to INNER JOIN statements. Focused on backend development using Java and SQL, the developer fixed incorrect handling of mixed-case aliases by ensuring aliases are properly escaped for case-sensitive recognition. This change improved the correctness of queries involving mixed-case aliases, reducing edge-case failures in production environments. To validate the solution, an integration test was added, expanding regression coverage and supporting ongoing stability. The work emphasized careful attention to database query correctness and thorough testing, contributing to more robust SQL parsing for complex join scenarios in Phoenix.