Re: preserve value order with referential integrity overlay?

[Howard Chu <hyc@symas.com>]

Zhang Weiwu wrote:
> Hello.
>
> I deployed an LDAP system and a set of applications around it that is
> highly sensitive to the order of values, e.g first telephoneNumber must
> be the main contact method, first value of companyRepresentative must be
> the DN of the main contact person.

That is a complete misuse of LDAP. Attributes are *SETS* of values. "Sets" are 
inherently unordered. The LDAP and X.500 specs and plenty of other docs tell 
you not to rely on the order in which values are returned.

> What's the best way to solve this problem? I can only think of 1) try to
> modify source code of slapo-refint to make it maintain order (big
> problem, never worked on C source code before, 

Obviously not the way to go.

or 2) try to use several
> attributes like "FirstCompanyRepresentative",
> "SecondCompanyRepresentative", "ThirdCompanyRepresentative"

Clumsy, and only feasible if you have a fixed limit on the number of values you 
want to manage.

You might consider something like
http://www.highlandsun.com/hyc/drafts/draft-chu-ldap-xordered-xx.html
which is only slightly less clumsy, and that spec needs to be revised anyway.
Whatever solution you choose is going to require your clients to be modified to 
adapt to the solution.
--
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP     http://www.openldap.org/project/