Erick,
On 22 Jul 2008, at 13:21, Erick Antezana wrote:
Hi Tim,
I installed the latest release (5.0.7) on a linux box (64bits) and
reloaded our data from scratch. Surprisingly some SPARQL queries that
were working previously are not anymore. We have not done a full test
but so far I found that in some cases I got a string: ''end reservoir"
while asking for the rdfs:label of a resource (I also get the right
label). On the other hand, I also faced some issues with: FILTER
regex(?term_name, "test") , it seems the regex doesn't do the job
anymore (things like FILTER bound (?name) work.)...Let me know if you
need any "explain" execution or so...
[Hugh] explain output for these problem queries would be useful to
see. Also, I presume you still have an instance of the previous
Virtuoso 5.0.6 build running when these queries run successfully, in
which case comparison explain queries would be useful to have also.
Another question: what is expected to happen with virtuoso if I am
loading some data in a specific graph and namespace and during that
loading process I launch a SPARQL query to the system asking something
from that graph/namespace? I've got an error (DBD::ODBC::st execute
failed: [unixODBC][OpenLink][Virtuoso iODBC Driver][Virtuoso
Server]SR172: Transaction deadlocked (SQL-40001)) from my loading
pipeline script. The loading process stops. It seems I cannot query
during the loading process?
[Hugh] This is most probably a transaction isolation level issue.
Note that when loading large RDF Data sets the default transaction
isolation setting should be READ COMMITTED, DefaultIsolation = 2 in
the [Parameters] section of the virtuoso configuration file
(virtuoso.ini)as detailed at:
http://docs.openlinksw.com/virtuoso/
rdfperformancetuning.html#rdfperfloadingunitpro
This will enable read access to committed data via an ODBC or any
other data access client.
You can also set the transaction isolation for your connection to
READ COMMITTED on the client also as detailed at:
http://docs.openlinksw.com/virtuoso/
ptune.html#TRANSACTION_ISOLATION_LEVELS
This can be done either using SQL you pass after connect :
SET TRANSACTION ISOLATION LEVEL READ COMMITTED
or at connect time using the following ODBC API call:
SQLSetConnectOption (hdbc, SQL_TXN_ISOLATION, SQL_TXN_READ_COMMITTED);
Note that READ COMMITTED by nature may provide unpredictable results
as it will only return data committed at the time the query is run.
Regards
Hugh
cheers,
Erick
Tim Haynes wrote:
Hi,
OpenLink Software is pleased to announce a new release of Virtuoso,
Open-Source Edition, version 5.0.7.
This release includes:
New: fully operational Native Graph Model Storage Providers for
the Jena &
Sesame Frameworks.
Licensing change: the Jena and Sesame providers have been added to
the
"Client Protocol Driver exemptions" paragraph in the
VOS License: http://virtuoso.openlinksw.com/dataspace/dav/wiki/
Main/VOSLicense
Improvements:
- Better support for alternate RDF indexing schemes
- Parallelization of RDF sponger operations across multiple RDF
data-sources concurrently
- New Sponger Cartridges and enhancements to the existing
Cartridge collection
- Inference engine optimizations for subclass and subproperty that
efficiently handle taxonomies numbering tens of thousands of classes.
- OWL equivalentClass and equivalentProperty inference support.
- Dynamic handling of host component of IRIs; host component is now
flexible enough to painlessly handle multiple homing of domains
and host
name component changes; no duplicate host name data storage required
via [URIQA] section of INI
- SPARQL optimizations to improve LIMIT and OFFSET handling
- JDBC driver has new connect options, smaller memory footprint and
optimized batch support
- ODS applications now support SyncML
Documentation Additions:
- How to read query plans and how to use the key performance meters
- How to diagnose SPARQL queries and how to decide what indexing
scheme is
right for each RDF use case
- How to debug RDF views
- Better Documentation on SPARQL extensions and options
- An updated RDF View example based on the Northwind demonstration
database
that reflects underlying enhancements
Bug Fixes:
- Generally improved safety of built-in functions, better argument
checking.
- Verified UTF8 internationl character support in all RDF use
cases, SQL
client/SPARQL protocol/all data formats.
For more details, see the release notes:
http://sourceforge.net/project/shownotes.php?
group_id=161622&release_id=614029
Other links:
Virtuoso Open Source Edition:
Home Page: http://virtuoso.openlinksw.com/wiki/main/
Download Page: http://virtuoso.openlinksw.com/wiki/main/Main/
VOSDownload
OpenLink Data Spaces:
Home Page: http://virtuoso.openlinksw.com/wiki/main/Main/OdsIndex
SPARQL Usage Examples (re. SIOC, FOAF, AtomOWL, SKOS):
http://virtuoso.openlinksw.com/wiki/main/Main/ODSSIOCRef
OpenLink AJAX Toolkit (OAT):
Project Page: http://sourceforge.net/projects/oat
Live Demonstration: http://demo.openlinksw.com/oatdemo
Interactive SPARQL Demo: http://demo.openlinksw.com/isparql/
OpenLink Data Explorer (Firefox extension for RDF browsing):
http://ode.openlinksw.com/
Regards,
~Tim
--
==================================================================
Erick Antezana http://www.cellcycleontology.org
PhD student
Tel:+32 (0)9 331 38 24 fax:+32 (0)9 3313809
VIB Department of Plant Systems Biology, Ghent University
Technologiepark 927, 9052 Gent, BELGIUM
er...@psb.ugent.be http://www.psb.ugent.be/~erant
==================================================================
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