Efficient Searching for Groups & its members

Hi All,

I am designing LDAP schema and the structure looks like :

--ROOT ---- ou = people ------- cn = john smith ---- ou = groups ------ ou = group1 -------- member:john smith ------ ou = group2 -------- member: john smith

I would like to find out what all groups john smith belongs to (I have full dn) and all the members of a group. I am wondering about the performance of such search, since one person can be part of multiple groups and there can be thousands of groups in the server. If its a relational database I can create a relationship table and put indexes in place. How can I get best performance with OpenLDAP? Or is there any other way I should design this?

Thanks for the help.