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From Emmanuel Lecharny <>
Subject Re: [ApacheDS][Partition] Using surrogate keys for attributeType aliases and objectClass aliases (was Re: [SCHEMA] Can two different LDAP AttributeType's have the same name?)
Date Fri, 06 Apr 2007 22:23:28 GMT
Ole Ersoy a écrit :

> Hmmm - Emmanuel - you said something
> interesting.
> The size of each entry is roughly 1kb.

It will depend on many parameters, but you have to keep in mind that you 
have the external form - ie, user provided - and normalized form. For 
instance, a DN is kept in both forms. If a user has a JpegPhoto, 1kb is 
not a minimum, it's simply impossible... Even with objectclasses (around 
3 values), operational attributes (creation date, creator, etc), 
description, SN, cn, etc, this will be at least a few hundred of bytes. 
Just look at any mail VCF card size :)

> When I start working on the ADS Design Guide
> there will be a section in there on the theoretical
> minimum size of an entry.

It's not theorical, it's real life.

> So what can be done to minimize the size?

Nothing. But is this really important ? Just think about the 80/20 rule 
(and it's much closer to a 95/5) : 20 percent of all entries will be 
accessed 80% of time. A good cache will usually gives you the same 
result (or close to) as if you put everything in memory. This is very 
basic IT theory...

> I think the Alex's mail and your link drive
> into that, so I'll try to consolidate those materials.

One more principle you should try to follow, as a general rule of thumb 
: KISS ( Complexity and 
over-engineered solution simply fail to meet any target ... When it 
works for 1000 entries, it should be possible to make it work for 10 
000. When it fails for 10 000, the odds are that it will also fail for 

> If anyone else has thoughts, I'll take them!

Here you are !

> Cheers,
> - Ole

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