Comment 2 for bug 1603540

Using "replace" instead of "add" is not entirely correct, as that will replace all existing indexes with the new ones. You will lose one of the most important indexes if you do that: "objectClass eq" :)

Out of the box, just after installing the slapd package, we get these:
olcDbIndex: objectClass eq
olcDbIndex: cn,uid eq
olcDbIndex: uidNumber,gidNumber eq
olcDbIndex: member,memberUid eq

We just need to add the missing ones.