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Re: rdf.rb/spira bulk read question

From: Ben Lavender <blavender@gmail.com>
Date: Wed, 2 Mar 2011 09:49:19 -0600
Message-ID: <AANLkTimPg8DME-pB900XA88bL5PGUprSmeY2ezpxFVFx@mail.gmail.com>
To: Greg Lappen <greg@lapcominc.com>
Cc: Gabor Ratky <gabor@secretsaucepartners.com>, public-rdf-ruby@w3.org
Currently, that is a correct understanding. I think we'd be willing to
accept a patch that checks if the given queryable has its own
implementation of Query#execute and uses that if found, and the
default if not. That should maybe even be the default, making
Query#execute call out to some method on Queryable that holds the
current BGP logic, which implementations can overwrite.

OTOH most implementations won't be able to do anything much more
effectively than the default algorithm. It is what it is.

If replication is your main goal, I'd suggest that several stores,
i.e. Sesame, can quite effectively use MySQL as a backend and you
could use that replication.

Ben

On Wed, Mar 2, 2011 at 9:37 AM, Greg Lappen <greg@lapcominc.com> wrote:
> Yes, not only am I using ipublic/rdf-couchdb, I WROTE it!  I'm pleasantly
> surprised to find that someone else has tried to use it, ha!
> I'd love input on how to make the implementation less naive...I have
> implemented the query_pattern method to use couchdb views instead of
> iterating over the entire repo, but is there more to it?  I think the
> looping behavior on the graph queries is a consequence of the graph query
> implementation, not the backend, right?
>
> On Wed, Mar 2, 2011 at 10:31 AM, Gabor Ratky <gabor@secretsaucepartners.com>
> wrote:
>>
>> Are you using Dan Thomas' rdf-couchdb project?
>> (https://github.com/ipublic/rdf-couchdb) I've found the project a naive
>> RDF::Repository implementation on top of CouchDB in many ways. Great proof
>> of concept with rdf-spec tests passing, but definitely needs work,
>> especially in the 'efficient querying' space, IMHO.
>> Are you taking a hard dependency on CouchDB in other parts of your
>> architecture (like us), or just chose it as an RDF repository?
>> Gabor
>> On Mar 2, 2011, at 3:20 PM, Greg Lappen wrote:
>>
>> Hi all,
>> We are making good progress with our project, and I've gotten to the point
>> where I am storing datasets in our rdf repository (rdf.rb based, implemented
>> on couchdb).  Now I'm building a page that allows the data to be exported in
>> various formats (xml, csv, etc), but when I iterate over all of the data, it
>> is extremely slow.  I see Spira querying the repository once for each
>> instance when I iterate using the model's "each" method.  I understand why,
>> I'm just wondering if there's a faster way to query all of the instances of
>> a Spira class.  One thought we had was to use a graph query instead, which
>> would pull out all the properties in N queries (where N is the number of
>> properties in the class).  In the example I'm trying, this would be 23
>> queries, which is better than hundreds or thousands of queries. Is this as
>> good as it gets?  I'm accustomed to working with RDBMS and ActiveRecord, so
>> I may just have to shift my expectations a bit, but thought I would ask the
>> group if there's something I'm missing....thanks as always,
>> Greg
>
>
Received on Wednesday, 2 March 2011 15:50:12 GMT

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