Up until now, customers using GROQ to limit the scope of Function invocations did not have access to the full suite of GROQ functions and features. Powerful abilities like Delta functions or document dereferences were unfortunately not supported in the initial release of Functions, and if you tried to deploy a Function using either of these features (among others), you would see an error during your Blueprint deployment.

However, that is no longer the case! You can now use the full power of GROQ with Functions.