Hi Drill Developers/experts, I hope you are all doing well.
I have been working on a geospatial architecture use case for a while now, researching the best way to handle large-scale Dutch coordinate transformations directly inside Apache Drill. Next week, I am planning to test my first working prototype / MVP for a custom Java Scalar UDF (rd_to_wgs84). The goal of this UDF is to perform high-performance, on-the-fly transformations from the Dutch Rijksdriehoekscoördinaten (RD New / Amersfoort, EPSG:28992) to global WGS84 coordinates (Latitude/Longitude, EPSG:4326). To maximize performance and avoid external GIS library overhead during runtime code generation, the MVP will implement the official Bessel-to-WGS84 polynomial regression formulas directly into the eval() method using primitive doubles, Netty DrillBuf writes, and a VarCharHolder output. Since Drill UDFs operate on a very specific subset of Java and rely heavily on internal scalar replacement, I want to make sure my implementation strictly adheres to Drill's compilation mechanics and memory management rules. Once the MVP and the Maven project are up and running next week, would anyone with experience in Drill's query engine internals and code generation be open to reviewing the Java code? I am planning to publish the final project as an open-source repository on GitHub to help the geospatial data engineering community. Any guidance or interest in doing a quick code review would be highly appreciated! Feel free to send me a private message at this email address, and we can discuss things privately between ourselves. Best regards, M.D
