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From Emmanuel Lecharny <>
Subject Re: [DAS] Unique IDs for Model Instances (Was Initial Context?)
Date Thu, 19 Apr 2007 08:12:54 GMT
Ole Ersoy a écrit :

> What should the RDN for each of these instances be?

Try to associate an *unique* key to each object, and used it

> We do that by getting the total number of children that
> the context cn=accounts, cn=users, cn=example, ou=com
> has, and then add 1.  So if there are 14 children, the
> new child gets a surrogate key assigned to it which is
> 15.

There is no way to get the number of entries in the server, but getting 
all the entries and count them. Not really fast.
Forget about your idea, it does not work.

> Then we write the surrogate key, along with a descriptive human
> readable/identifiable string (Like "Alex Karasulu") taken from one of 
> the root object's attributes

Just use this object's attribute as the RDN.

> <snip>

> Originally I was was thinking generate a surrogate key using a hash,

Don't. Hash are not guaranteed to be unique. Java HashCode is just a 
speedup for comparisons.
o1.hashcode != o2.hashcode() => o1 != o2
o1.hashcode == o2.hashcode() does not implies that o1 == o2


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