Re: Unquoted column names fold to lower case

And let's not forget that column aliases can be used as indentifiers in
queries:

        test=> SELECT 1 AS x
        test-> ORDER BY x;
         x
        ---
         1
        (1 row)

        test=> SELECT 1 AS "X"
        ORDER BY x;
        ERROR:  column "x" does not exist
        LINE 2: ORDER BY x;

Changing this would mean that the same identifier would have different
case-folding rules depending on where it appeared in the query.