Cloud SQL instances run in a managed environment. A UDF contains code that becomes part of the running server, which is difficult to accommodate in this environment. Why is this feature needed for your project? Is there no other option available? A feature request needs the support of a well-motivated use-case to prove its point and convince. A detailed description, preferably in step-by-step format, would be appreciated. Feature requests are closely examined and followed in the
Public Issue Tracker, you are encouraged to open one there.