During November 2025, Vitus Wagner enhanced the GreengageDB/greengage repository by addressing a complex bug in distributed query planning. He focused on improving the reliability of subplans involving correlated functions and master-only or replicated tables, which previously led to execution errors in distributed environments. Using his expertise in PostgreSQL, database development, and query optimization, Vitus ensured that the system correctly handles parallelization and materialization of functions within distributed plans. His work resulted in more robust execution and safer parallel processing, reflecting a deep understanding of distributed database internals and careful attention to the nuanced challenges of query planning in C.