Jena slow ontology population

["villa.va@libero.it" <vi...@libero.it>]

Dear users, 

I am new to Jena and have a problem with Jena OWL-API. I have written some 
simple Java code that:

1) extracts some tuples (around 1 million tuples) of data from a database
2) puts each of them in an ontology file using Jena library. In particular, it 
takes every tuple and inserts 
every element in a class of the ontology file, by using methods like 
createIndividual, addproperty, model.write.

The insertion phase is very quick when my program starts, but the performances 
became worse and worse as 
time goes by. The DB man has told me that the database has no problems. I have 
run the program with 5 gigabytes
of RAM...it simply ends up to use them all. Is that normal? Do I have to use a 
more powerful PC to manage such 
data? I can give you more details about my problem if you tell me what I have 
to look for exactly.

Thanks a lot,

Paola

Re: Jena slow ontology population

[Marco Neumann <ma...@gmail.com>]

can you please be a bit more specific about the configuration you have
currently installed? e.g. version of Jena, back end type (TDB, SDB,
in-memory), current hardware, and OS (32bit, 64bit, linux,
windows,mac), and type of reasoner you use.

---
Marco Neumann
KONA

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On Fri, Mar 30, 2012 at 4:22 AM, villa.va@libero.it <vi...@libero.it> wrote:
> Dear users,
>
> I am new to Jena and have a problem with Jena OWL-API. I have written some
> simple Java code that:
>
> 1) extracts some tuples (around 1 million tuples) of data from a database
> 2) puts each of them in an ontology file using Jena library. In particular, it
> takes every tuple and inserts
> every element in a class of the ontology file, by using methods like
> createIndividual, addproperty, model.write.
>
> The insertion phase is very quick when my program starts, but the performances
> became worse and worse as
> time goes by. The DB man has told me that the database has no problems. I have
> run the program with 5 gigabytes
> of RAM...it simply ends up to use them all. Is that normal? Do I have to use a
> more powerful PC to manage such
> data? I can give you more details about my problem if you tell me what I have
> to look for exactly.
>
> Thanks a lot,
>
> Paola