The answer is that you are thinking as indexes in the context of fast lookup
on fields.
However my requirement comes from a need to ensure that every single field
in the
table forms a unique combination. (not my design, I might add)
Now you know why, can you append it to the TODO list?
On thinking about it, I wonder if the same field can appear more than
once in an index. Now that would be weird!
>> 1. Have more than 7 fields on a btree index
>
>We have never understood why someone would want an index with more than
>seven columns.
>
>--
> Bruce Momjian | http://www.op.net/~candle