"Frank D. Engel, Jr." <fde101@xxxxxxxxxxx> writes:
> I'm sure this won't work for some reason, but something similar might; why not
> create a unique index on a constant where all three are null; something along
> these lines (in addition to the others):
>
> CREATE UNIQUE INDEX foo_trio_index ON foo (1) WHERE c IS NULL AND a IS NULL and
> b IS NULL;
>
Huh. Hadn't thought of creating an index on a constant. It works if you put an
extra set of parentheses in:
CREATE UNIQUE INDEX foo_abc_index ON foo ((1)) WHERE ...
--
greg
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
