Thanks all for your input!
I've updated FLIP-57 accordingly. To summarize the changes:
- introduced new concept of "Temporary system functions", which has no
namespace and override built-in functions
- repositioned "temporary functions" to be those with namespaces and
override catalog functions
- updated FunctionCatalog APIs
- redefined the ambiguous function resolution order to be:
1. temporary system functions
2. builtin functions
3. temporary functions, of the current catalog/db
4. catalog functions, in the current catalog/db
Since we've reached consensus on several most critical pieces of the FLIP,
I've started a separate voting thread on it.
Cheers,
Bowen
