>>
>> > Would a rule be that
>> > if the first attribute of an index is unique, then additional
>> > attributes are basically useless?
>>
>> For PostgreSQL this is currently true, since indexes are
currently not
>> used for order by. If you have a unique first column in an index,
>> then all following columns could only be used for sorting,
>> not for faster access (access actually gets worse).
>
>Sorry, don't follow this logic. He is not restricting on the first
>field of the index, so the index is not used.
Ooops, I did not look at that, I just took the sentence standalone,
and under the presumption that the first field of the index is in the where
restriction.
Andreas