Strange behaviour regarding index

[melo@isp.novis.pt]

hi!

i'm setting up a qmail-ldap server. the queries made by the qmail server
are like this:
(|(mail=someone@somedomain.pt)(mailAlternateAddress=someone@somedomain.pt))

In my slapd.conf I have:
index           objectClass,mail,mailAlternateAddress,uid eq

but rigth now, I dont have a single entry with a mailAlternateAddress
attribute.

I inserted all my data and the mailAlternateAddress is not created.

The problem with that is that the query above becomes real slow, because
it has to search over the full tree for entries with mailAlternateAddress
attributes.

Questions:
 1. is this a bug?
 2. apart from adding a fake entry with a mailAlternateAddress attribute,
    can I force that index to be created?

Best regards,

-- 
Pedro Melo Cunha - <melo@isp.novis.pt>
Novis - Dir. Rede - ISP - Infraes. Portal <http://www.novis.pt/>
Ed. Atrium Saldanha - Pça. Dq. Saldanha, 1 - 7º / 1050-094 Lisboa
tel:  +351 21 0104340  - Fax: +351 21 0104301