Towards Database Query Optimizers that understand UDFs (5/7/2025)
Towards Database Query Optimizers that understand UDFs
In modern database systems, User-Defined Functions (UDFs) have become indispensable for encapsulating logic that goes beyond traditional SQL capabilities. Yet, despite their ubiquity, UDFs remain a thorn in the side of query optimizers. Conventional cost models often treat UDFs as black boxes or rely on static assumptions, which can lead to suboptimal execution plans. With GRACEFUL (GRAph-based Cost Estimator For User-defined Logic), we have published a novel approach tackling this decades-old challenge.
