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Re: [Fwd: Major technical comment: identifier length]

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Thu, 12 Jan 2006 21:42:21 -0500
Message-Id: <c648d7f96a164e3195b90bcc3c74af1c@isr.umd.edu>
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
To: Dan Connolly <connolly@w3.org>

On Jan 12, 2006, at 7:05 PM, Dan Connolly wrote:

> I don't think there's any WG decision that I can cite
> in response to this comment; I don't think we considered
> identifier length, except inasmuch as we OK'd the grammar.
>
> I suppose it might be useful to specify that identifiers
> longer than, say, 1024 characters aren't guaranteed
> to work.

I don't see that that's particularly useful. I mean, what' more likely  
to be an issue in an implementation is total number of variables in a  
query. 1024^nrofqueryvariablenamecharacters is a frickin lot of  
variables ;)

Also, I don't think that we should limit the number of variables in a  
query.

I searched around for some limits:

	http://www.oracle.com/technology/support/tech/sql_plus/htdocs/ 
sub_var6.html
	http://web.njit.edu/info/limpid/DOC/server.920/a90842/apa.htm
	http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp? 
topic=/db2/rbafzmstlimtabs.htm

I mean, 128 chars....if we are talkin 1024 we should just say arbitrary  
:)

> On the other hand, Java seems to get away with silence
> on this issue...
>
> http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.8
>
> Does anybody have implementation-defined limits in their code?

Since you already have to parse arbitrarily sized bits of data  
(including identifiers such as URIs), I think length of identifier  
doesn't matter *except* insofar as it constrains number of variables.  
And the kinds of constraints we are talking about (e.g., 1024) doesn't  
constraint *that* very effectively...so...why bother?

Cheers,
Bijan.
Received on Friday, 13 January 2006 02:42:30 GMT

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