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Re: Mulgara and sameTerm

From: Paul Gearon <gearon@ieee.org>
Date: Tue, 29 Jul 2008 11:16:28 -0500
Message-ID: <a25ac1f0807290916x2d48a77fpda26f817807bc9ce@mail.gmail.com>
To: "James Leigh" <james-nospam@leighnet.ca>
Cc: public-sparql-dev@w3.org, "Seaborne, Andy" <andy.seaborne@hp.com>, "Arjohn Kampman" <arjohn@aduna-software.com>, "Andrae Muys" <andrae@netymon.com>

On Tue, Jul 29, 2008 at 10:49 AM, James Leigh <james-nospam@leighnet.ca> wrote:
> On Tue, 2008-07-29 at 10:44 -0500, Paul Gearon wrote:
>> Because I was being asked to make this "work" with the SPARQL test
>> suite, I presumed that duplication was required. I also presumed that
>> most applications inserting a non-canonical form of data would stick
>> to the same lexical form each time, which would minimize the issue for
>> that application.
>>
>> Of course, it is always possible to take the easy road and rely on
>> RDF-equals. So instead of using:
>>   ns:foo ns:bar ?x . ?x ns:baz ns:boo
>>
>> You'd instead use:
>>   ns:foo ns:bar ?x . ?y ns:baz ns:boo FILTER (?x = ?y)
>>
>> However, this is never going to perform as well, and can potentially
>> take up significantly more storage, so I'm not for it at all.
>>
> If this brakes SPARQL compatibility, would you be against full SPARQL
> compatibility in Mulgara?

No. I do see standards compliance as vital.

My point was that I'd like to see some way to use joins, and not rely
on RDF-equals. However, I was also acknowledging that RDF-equals
provides the necessary functionality if joins don't work for us. I
just don't like it because filters cost more than joins.

I suppose I should be grateful that this only affects certain
datatypes for literals, and doesn't affect URIs or blank nodes. So
even if we have to go down the inefficient route the pain will be
contained.

Regards,
Paul
Received on Tuesday, 29 July 2008 16:17:05 GMT

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