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1. Re: What are RDFB_modelname and RDFC_modelname ?
766393 Jun 11, 2010 4:29 PM (in response to 766393)Another related question : What is the difference between the triple table (modelname_tpl) and the mdsys.semm_modelname table. I have not been able to find any information about these in the documentation.
Thanks.
Regards,
Julien -
2. Re: What are RDFB_modelname and RDFC_modelname ?
JorgeB-Oracle Jun 11, 2010 6:52 PM (in response to 766393)Hi,1 person found this helpful
Answering just the second question:
The triple table
CREATE TABLE BOOKSTORE_rdf_data
(id NUMBER, triple SDO_RDF_TRIPLE_S);
just holds the triples as numbers (ids)
When you create the model:
execute SEM_APIS.create_sem_model
('bookstore', 'bookstore_rdf_data', 'triple');
The view SEMM_BOOKSTORE is created
SEMM_model_name is a view with its definition based on rdf_link$ which is a partitioned table that holds all models created in the database. The SEMM_model_name is the view that represents your model in RDF_LINK$ table.
The triple table
set long 9000000
select text
from user_views where view_name = 'SEMM_BOOKSTORE';
TEXT
--------------------------------------------------------------------------------
select "P_VALUE_ID","START_NODE_ID","CANON_END_NODE_ID","END_NODE_ID","MODEL_ID"
,"COST","CTXT1","CTXT2","DISTANCE","EXPLAIN","PATH","LINK_ID" from rdf_link$ par
tition (model_3)
Hope this clarifies.
Further note. RDF_LINK$ holds ids, the real values are in RDF_VALUE$
Regards!
Jorge -
3. Re: What are RDFB_modelname and RDFC_modelname ?
766393 Jun 14, 2010 10:06 AM (in response to JorgeB-Oracle)Thanks a lot for your help.
However, there is still something I do not understand.
The triple table and the SEMM_modelname view both contain as many lines as there are triples in my model, don't they ?
In my case, a count on the triple table returns 16678194 while a count on the view returns 15704099.
Where does the difference come from ?
Thanks
Regards
Julien -
4. Re: What are RDFB_modelname and RDFC_modelname ?
715399 Jun 14, 2010 1:56 PM (in response to 766393)Hi,1 person found this helpful
The reason for the discrepancy is that the application table allows duplicates, whereas there are no duplicate triples stored in the model.
Vladimir -
5. Re: What are RDFB_modelname and RDFC_modelname ?
JorgeB-Oracle Jun 14, 2010 1:59 PM (in response to 766393)*
Edited by: jbarba on Jun 14, 2010 9:59 AM -
6. Re: What are RDFB_modelname and RDFC_modelname ?
766393 Jun 15, 2010 2:02 PM (in response to 715399)OK, thanks for your help.
I thought duplicates were dealt with during the insertion of triples (since in my case, inserts are getting significantly slower when there is already some triples in the model Insert several millions of triples : which solution is the fastest ?
To come back to my first question : What are RDFB_modelname and RDFC_modelname ?
Regards,
Julien -
7. Re: What are RDFB_modelname and RDFC_modelname ?
715399 Jun 15, 2010 2:11 PM (in response to 766393)Hi Julien,
RDFB_model and RDFC_model are temporary (staging) tables used during bulk loading. They are defined as global temporary tables so when the session ends all of the data in those tables is deleted.
Vlad