Re: multiple UNIQUE indices for FK

>
> W dniu 23.02.2016 o 09:39, Rafal Pietrak pisze:
> > Can anybody suggest any other way out of this mass?
>

​The only thought that sticks while reading your prose is:​

​message ----> message-person <---- person​

​message-person (message_id, person_id, relationship_type[sender, receiver])

Partitioning and partial indexes both have considerable limitations that
you might need to work around. That said normalization exists for a reason
and having multiple "person" columns in a table is a form of duplication
that if left presents just the problems you are seeing.

I suspect your SSN should fit onto the message-person table.

The following doesn't make sense - if the SSN is sender unique then there
is no expectation that a receiver would not receive two messages with the
same SSN from different senders.
ALTER ... msgs_to_me ADD CONSTRINT them_uniq UNIQUE (THEM,SSN);

David J.