Conditional Compilation in 11g

If yesterday's post got you in the mood to investigate Oracle 11g, here is a quick demonstration of the resultant end of your conditional compilation usage.

CREATE OR REPLACE FUNCTION return_junk RETURN dual.dummy%TYPE
$IF dbms_db_version.ver_le_10 $THEN 
$ELSE RESULT_CACHE $END 
IS
  lc_dummy  dual.dummy%TYPE;
BEGIN
   SELECT dummy
   INTO   lc_dummy
   FROM   dual;
 
   RETURN lc_dummy;
END return_junk;
/

In the accompanying image, you can see I've determined what the interpreted code will be, compiled in 11g, the RESULT_CACHE feature is present. Had I compiled this in 10g, line 2 & 3 will be completely clear and you would not have 11g technology causing syntax errors in your 10g database.

Of course, so you can remind yourself during the migration to 11g to test these concepts in development first, you would code with an error directive:

CREATE OR REPLACE FUNCTION return_junk RETURN dual.dummy%TYPE
$IF dbms_db_version.ver_le_10 $THEN 
$ELSE RESULT_CACHE $END 
IS
  lc_dummy  dual.dummy%TYPE;
BEGIN
$IF dbms_db_version.ver_le_10 $THEN 
$ELSE
   $ERROR '11g upgrade in process. This component needs further testing'
   $END
$END  

   SELECT dummy
   INTO   lc_dummy
   FROM   dual;
 
   RETURN lc_dummy;
END return_junk;
/

Which on compilation will give
Error(9,4): PLS-00179: $ERROR: 11g upgrade in process. This component needs further testing

At least you added in the code when you became aware of it a it didn't get forgotten about!