Within all Oracle versions there were some features about I heard a lot something like: "well this feature is not quite ready now but it will be within the next Oracle version". This was the case for the "Oracle Resource Manager" in 9i, or for the "Oracle Managed Files" feature. Both of them were made available in 9i but many DBAs, including me, felt that they were not really ready for production. Only starting with Oracle 10g I could figure out that the strength of the OMF was especially in connection with ASM (Automatic Storage Management) and, just beginning with this version, the "Resource Manager" component had been improved quite enough to become appealing for a productive environment.
Now, I have the same feeling regarding the named and mixed notation for USER DEFINED PL/SQL functions, when they are invoked in a SQL context. For me, it was a common error in Oracle previous releases to write something like:
select dbms_random.string(opt => 'L', len => 10) from dual;
Of course, an error was raised because the SQL context doesn't know how to handle named parameters, but there is also true that when you are using an IDE like PL/SQL Developer or other powerful tools which provide code completion, it is almost impossible not to be tempted by such a feature, being sometimes hard to avoid the above mistake. However, the above code is perfectly valid in Oracle 11g. What really bothers me here is that I cannot use this approach for all functions. For example:
SQL> select regexp_count(srcstr => 'tralala', pattern => 'a') from dual;
select regexp_count(srcstr => 'tralala', pattern => 'a') from dual
ORA-00907: missing right parenthesis
Bleah, ugly! At least it is working for DBMS packages which is a great plus. But, anyway, for me it's a feature which is not "quite ready" but I hope it will be in Oracle 12g... maybe.