> > All the FB articles/docs/postings that I have seen have said for
> > performance, index depth should be no more than 3.
>
> This is not a hard requirement, 4 levels may be also OK. Are those multi-
> segment indices primary/unique keys or just for lookup purposes?

{Sorry for the delay in responding, was away on vacation}

Most of our PK are generator values, the multi-segment indexes are to optimize commonly used queries.


Sean