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Posted to dev@marmotta.apache.org by FRANCISCO XAVIER SUMBA TORAL <xa...@ucuenca.ec> on 2015/05/07 19:54:11 UTC
[jira] [Commented] (MARMOTTA-584) Add GeoSPARQL support to KiWi
triple store
Such as I mentioned in my proposal:
https://www.google-melange.com/gsoc/project/details/google/gsoc2015/fernandobac03/5707702298738688
two
possible ways for implement GeoSPARQL over marmotta were described.
1. Materialization of Triplets
Advantages
• Fast GeoSPARQL query
Disadvantages
• Materialization is a large process
• The materialization requires more storage capacity than traditional
strategies
• Implies native tools, operators handling (postgresql)
2. Native support and query translation
In this case, the GeoSPARQL query is translated to spatial operators and
executed by native tools (GeoTools).
Advantages
• Direct comparison
• Optimal storage
• There is no need to manipulate the native functionality
Disadvantages
• Slow GeoSPARQL querying
After the analysis of both situations, I have decided to work with the
"Native Support and Query Translation"
The "materialization of triplets" will depend of the amount of information
stored at the moment in Marmotta
If more information exists, more time will be needed to upload the new data
because the spatial relations are analyzed at this time
However, with the "Native Support and query translation" the spatial
analysis will be executed at the time the query is executed.
And no need manipulate the native functionality.
Re: [jira] [Commented] (MARMOTTA-584) Add GeoSPARQL support to KiWi
triple store
Posted by FRANCISCO XAVIER SUMBA TORAL <xa...@ucuenca.ec>.
Mira en este correo dice que me puede dar los permisos para la wiki. Le
digo que me asigne los permisos, si hay algún formato para los post.
Saludos
On May 11, 2015 1:31 AM, "Sergio Fernández" <wi...@apache.org> wrote:
> Hi Francisco,
>
> welcome on board, and congratulations for the grant of your project!
>
> On Thu, May 7, 2015 at 7:54 PM, FRANCISCO XAVIER SUMBA TORAL <
> xavier.sumba93@ucuenca.ec> wrote:
> >
> > After the analysis of both situations, I have decided to work with the
> > "Native Support and Query Translation"
> >
>
> I think that approach would better for us, since the KiWi triplestore
> basically maps the SPARQL queries directly to SQL. Therefore we can add
> GeoSPAQL aligned with that, reusing the native geo capabilities that
> PostGIS provide, right?
>
> We already worked on that direction to support better full text search in
> SPARQL. I'd recommend you to start taking a look how that extension is
> implemented. You can find some documentation at:
>
> http://marmotta.apache.org/kiwi/sparql.html#Marmotta_Extensions
>
> If you think is interesting, I can grant you access to our wiki to start to
> write down such things up from the beginning.
>
> Thanks!
>
> --
> Sergio Fernández
> Partner Technology Manager
> Redlink GmbH
> m: +43 6602747925
> e: sergio.fernandez@redlink.co
> w: http://redlink.co
>
Re: [jira] [Commented] (MARMOTTA-584) Add GeoSPARQL support to KiWi
triple store
Posted by Sebastian Schaffert <se...@gmail.com>.
Hi,
some minor comments :)
2015-05-11 8:30 GMT+02:00 Sergio Fernández <wi...@apache.org>:
> Hi Francisco,
>
> welcome on board, and congratulations for the grant of your project!
>
> On Thu, May 7, 2015 at 7:54 PM, FRANCISCO XAVIER SUMBA TORAL <
> xavier.sumba93@ucuenca.ec> wrote:
> >
> > After the analysis of both situations, I have decided to work with the
> > "Native Support and Query Translation"
> >
>
> I think that approach would better for us, since the KiWi triplestore
> basically maps the SPARQL queries directly to SQL. Therefore we can add
> GeoSPAQL aligned with that, reusing the native geo capabilities that
> PostGIS provide, right?
>
Actually it can be a mix of both approaches. What I'd recommend is to use
PostgreSQL triggers to materialize *some* of the data, and then rely on
query translation to PostGIS constructs like Sergio suggests. What you
could then do is, whenever a "location" literal (or whatever combination of
triples) is added or removed, trigger updating a separate table with geo
information that allows specialized geo access. Another option is to create
a VIEW on the triples and nodes tables that allows for this access. A view
can then later be materialized (or partly materialized) if needed.
>
> We already worked on that direction to support better full text search in
> SPARQL. I'd recommend you to start taking a look how that extension is
> implemented. You can find some documentation at:
>
> http://marmotta.apache.org/kiwi/sparql.html#Marmotta_Extensions
>
> If you think is interesting, I can grant you access to our wiki to start to
> write down such things up from the beginning.
>
>
Since I implemented most of the database support, please don't hesitate to
ask me, even if I might be a bit slow to react with my move to my new job
at Google.
Sebastian
Re: [jira] [Commented] (MARMOTTA-584) Add GeoSPARQL support to KiWi
triple store
Posted by Sergio Fernández <wi...@apache.org>.
Hi Francisco,
welcome on board, and congratulations for the grant of your project!
On Thu, May 7, 2015 at 7:54 PM, FRANCISCO XAVIER SUMBA TORAL <
xavier.sumba93@ucuenca.ec> wrote:
>
> After the analysis of both situations, I have decided to work with the
> "Native Support and Query Translation"
>
I think that approach would better for us, since the KiWi triplestore
basically maps the SPARQL queries directly to SQL. Therefore we can add
GeoSPAQL aligned with that, reusing the native geo capabilities that
PostGIS provide, right?
We already worked on that direction to support better full text search in
SPARQL. I'd recommend you to start taking a look how that extension is
implemented. You can find some documentation at:
http://marmotta.apache.org/kiwi/sparql.html#Marmotta_Extensions
If you think is interesting, I can grant you access to our wiki to start to
write down such things up from the beginning.
Thanks!
--
Sergio Fernández
Partner Technology Manager
Redlink GmbH
m: +43 6602747925
e: sergio.fernandez@redlink.co
w: http://redlink.co