It is 1/2 a dozen of one, 1/2 a dozen of the other ...

We "store forward links", but AD defines a table, with indices such that
we have an efficient way to lookup backlinks for a given object.  Don't
have time right now to show you what I mean, but my Daddy says there are
24 usable hours in the day, so maybe at 3 AM ...

Cheers,
BrettSh


On Fri, 9 Jun 2006, Willem Kasdorp wrote:

> Hi, 
> 
>  
> 
> I was just reading Tony's article
> 
> (http://www.activedir.org/article.aspx?aid=92) on linked attributes, and
> encountered something that I wondered about. This section "Why have linked
> attributes?" says:
> 
>  
> 
> "I haven't seen an official explanation, but I can think of two reasons why
> they would be useful.  The first is consistency.  By storing one half of the
> link only in the directory database, it ensures that queries for the back
> link attribute values are always consistent with the information stored in
> the forward link.  The second reason is that it is an efficient means of
> storage in the directory database and keeps the space used to a minimum." 
> 
>  
> 
> My guess would be that the primary function of back links is to enable
> efficient backward lookups: of which groups is this user a member? Secondly,
> the quote suggests that the backlinks are not stored in the database. I'd
> think they are stored there because it would be pretty hard/inefficient to
> calculate them on the fly, but that they are not replicated. 
> 
>  
> 
> Anybody care to comment?
> 
>  
> 
> --
> 
>  
> 
>    Cheers, Willem.
> 
>  
> 
>  
> 
> 

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