RE: Use of BITS construct in table indices

Actaully I think it is:

   N = (7 + M)/8  where M is highest bit value

Thanks,
Bert 

> -----Original Message-----
> From: Knotts, Jay B (Jay) [mailto:[email protected]]
> Sent: donderdag 14 november 2002 15:45
> To: [email protected]
> Subject: RE: Use of BITS construct in table indices
> 
> 
> 
> This is the correct formula for calculating string length of 
> BITS? Just wanted to make sure. 
> 
> 
> >> I am inclined to believe that it is considered a 
> variable-length string,
> >> and subject to being encoded with (N+1) subidentifiers where
> >> N = (M + (M % 8))/8, M = highest bit value supported by an 
> implementation,
> >> unless it is an IMPLIED index. 
> 
> Jay Knotts 
> 
> 
> -----Original Message-----
> From: Juergen Schoenwaelder [mailto:[email protected]]
> Sent: Thursday, November 14, 2002 9:06 AM
> To: [email protected]
> Cc: [email protected]
> Subject: Re: Use of BITS construct in table indices
> 
> 
> 
> >>>>> Michael Kirkham writes:
> 
> Michael> RFC 2578 is a bit vague on the legality and implications of
> Michael> using objects of type 'BITS' as an INDEX.  It's not
> Michael> explicitly forbidden, and seems to be legal given that it is
> Michael> otherwise indistinguishable from an OCTET STRING.  If it's
> Michael> legal, then, for purposes of encoding the instance identifier
> Michael> for a columnar object, is it considered a fixed-length or a
> Michael> variable-length OCTET STRING (since new bits can be added
> Michael> over time)?
> 
> RFC 2578 section 7.7 page 28:
> 
>    Since a single value of a Counter has (in general) no information
>    content (see section 7.1.6 and 7.1.10), objects defined using the
>    syntax, Counter32 or Counter64, must not be specified in an INDEX
>    clause. If an object defined using the BITS construct is used in an
>    INDEX clause, it is considered a variable-length string.
> 
> I think the last sentence provides a clear answer to your question.
> 
> /js
> 
> -- 
> Juergen Schoenwaelder    
<http://www.informatik.uni-osnabrueck.de/schoenw/>