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From Alex Karasulu <akaras...@apache.org>
Subject Re: OID size limit?
Date Thu, 28 Dec 2006 21:46:17 GMT
Can't us just use a separate attribute for the correlation instead of
using an OID?

Alex

Tino Schwarze wrote:
> Hi Emmanuel,
> 
> On Thu, Dec 28, 2006 at 03:56:50PM +0100, Emmanuel Lecharny wrote:
> 
>> so far, OID parts are stored in java long, so into the interval [-2^63,
>> 2^63-1]. You can use up to 19 digits for an element of an OID, so your
>> sample won'ty be accepted.
>>
>> If you want to generate "random" OID, what I suggest is that you store 32
>> bits values separated by a '.', like :
>>
>> 1.3.6.1.4.1.<myprivateOID>.0.<first 32 bits value>.<second 32 bits
value>.
>> ... .<last 32 bits value>.
> 
> Oh, I see. That's rather cumbersome and would clutter the structure a
> lot. Well, one's not supposed to parse the structure anyway...
> 
>> Do also remember that, in LDAP, OID are used to declare new attribute types,
>> so creating arbitrary long OID does not make a lot of sense, but as I'm not
>> aware of all the possible use-cases...
>>
>> I would be very interested to know why you need such OID values.
> 
> Well, I'd like to create an automated open-EIS to LDAP mapping. In
> open-EIS we've got so-called templates (which are basically RDBMS tables
> with lots of sugar and niceties like multi-language support etc.). A
> template has a uniqe name called GUID, e.g. "c4u_classic_email". To
> avoid having to assign a unique template OID for each open-EIS template
> (extending the data model etc.), I just took the template GUID (which
> consist of [a-zA-Z0-9_] and is up to 128 characters long) and converted
> it to a number.
> 
> That way, the template GUID -> OID mapping is unique and I don't need a
> central registry (which is rather cumbersome because third parties may
> develop open-EIS modules themselves and currently, they don't need to
> tell us; then they'd need to apply for template OID, wait for it etc.).
> 
> I'll try the 32-bits approach (BTW why 32 and not 42? ;-) ).
> 
>>> is there any known limitation of OID size or the size of an OID part?
>>> I'm going to use auto-generated OIDs and they will look like:
>>> 1.3.6.1.4.1
>>> .<myprivateOID>.0.8228681198498217497059596.0.7212074495361812662326490325180684
>>>
>>> The OID BNF grammar doesn't specify any limits, so I'm only wondering
>>> whether there are known real-life limits. Will performance be affected
>>> by these monsters?
> 
> Thanks,
> 
> Tino.
> 


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