Reece Hart <reece@xxxxxxxxx> writes:
However, it's not clear that you've considered a clause like 'ORDER BY
(foo IS NULL), foo', which I believe is not implementation dependent.
Yeah, that should work reasonably portably ... where "portable" means
"equally lousy performance in every implementation", unfortunately :-(.
I rather doubt that many implementations will see through that to decide
that they can avoid an explicit sort.
Well, an index on ((foo IS NULL), foo) might improve the performance
when sorting along these columns, but sure it's not a cure-all. And you
still have to modify the SQL and the database schema ...
regards
TV
---------------------------(end of broadcast)---------------------------
TIP 6: explain analyze is your friend
