SELECT DISTINCT concat(database_name, '.', schema_name) AS name
FROM duckdb_functions()
WHERE database_name = 'system'
UNION ALL
SELECT DISTINCT concat(database_name, '.', schema_name, '.', function_type) AS name
FROM duckdb_functions()
WHERE database_name = 'system'
UNION ALL
SELECT DISTINCT concat(database_name, '.', schema_name, '.', function_type, '.', function_name) AS name
FROM duckdb_functions()
WHERE database_name = 'system'
UNION ALL
SELECT DISTINCT concat(database_name, '.', schema_name, '.', function_type, '.', function_name, '.', return_type) AS name
FROM duckdb_functions()
WHERE database_name = 'system'
-- DESCRIBE SELECT * FROM duckdb_functions()