pgsql-bugs@postgresql.org writes:
> select date_fld from my_table order by date_fld desc;
> The above query put NULLs on top of normal values
> in stead of bottom, this is not the case in 7.1.3.
This is not a bug; it is an intentional change in behavior to conform
to SQL92. We are not going to change it back --- unless you can
convince us that our reading of the spec is incorrect.
regards, tom lane