OpenLink Virtuoso (Open-Source Edition)

hi,

did you double check that 
stmt.executeQuery(query); 
doesn't throw an exception?

i'd have a try with stmt.executeUpdate
and check the resulting int is gt 0.
if so try a rollback.

wkr turnguard

----- Original Message -----
From: "Alex" <nheadmaster@...>
To: virtuoso-users@...
Sent: Friday, July 6, 2012 6:03:20 PM
Subject: [Virtuoso-users] Rollback via java


Hi, 


I am trying to test rollback via the java driver. I insert first the following triple via isql: 


sparql INSERT INTO < http://mygraph.com > { < http://myopenlink.net/dataspace/Kingsley#this > < http://www.w3.org/1999/02/22-rdf-syntax-ns#type > < http://rdfs.org/sioc/ns#User > }; 


The insertion was successful and I can see the graph. Then I execute the following code: 



conn.setAutoCommit(false); 

stmt = conn.createStatement(); 

String query = "sparql clear graph< http://mygraph.com >"; 

stmt.executeQuery(query); 

conn.rollback(); 

stmt.close(); 

conn.setAutoCommit(true); 


I go then to isql but the graph does not exist. What is wrong? 


There was also a relevant question in the forums ( http://boards.openlinksw.com/phpBB3/viewtopic.php?f=12&t=431 ) back to 2009. 
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The virtuoso version is  version 0.9849b.
The number of triples in the store is about 220M triple (the dbpedia dump)
The virtuoso.ini file : http://pastie.org/4216107

RAM disk is a tool that converts the memory into an accessable partition,
it's a straight forward tool with a single command to allocate and
deallocate memory.
the tool I use is called ImDisk, it's a freeware command-line based tool
After creating the partition, I used benchmarking tools to benchmark the
read and write speeds of the partition, it was sky-rocketing (about 3GB/s
Read and write speeds) , alot faster than any commercial SSD on the market.

On Sat, Jul 7, 2012 at 6:01 PM, Hugh Williams <hwilliams@...:

> Hi Sherif,
>
> Please provide more details on:
>
> 1. The Virtuoso version being used by running the command,  “virtuoso-t -?”
> 2. The number of triples in the Virtuoso Quad Store
> 3. Provide a copy of your “virtuoso.ini” file
> 4. The output of running the command, “status(‘’)” from isql
> 5. More details on how exactly RAM Disk has been configured on your system
>
> I assume you have performance tuned your Virtuoso server as detailed at:
>
>
> http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtRDFPerformanceTuning
>
>   Best Regards
> Hugh Williams
> Professional Services
> OpenLink Software, Inc.      //              http://www.openlinksw.com/
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> Google+  -- http://plus.google.com/100570109519069333827/
> Facebook -- http://www.facebook.com/OpenLinkSoftware
> Universal Data Access, Integration, and Management Technology Providers
>
> On 7 Jul 2012, at 07:23, sherif kandel wrote:
>
> I bought 32GB RAM for my  machine, I used a software called "RAM Disk"
> That can take part of the RAM and turns it into a storage partition for
> you, of course with the speed of the RAM (3GB/s Read and write speeds) it's
> 7 times faster than an ordinary SSD.
>
> The problem is that didn' t make my queries even close to 7 times faster,
> if anything, the queries are about twice faster. I understand the overhead
> for processing queries. but is there's anything in the INI file I can set
> to fasten things up a little ? I use 26GB from RAM for the dbpedia dump and
> 2GB as RAM for virtuoso and the rest is for the rest of the system.
> ------------------------------------------------------------------------------
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> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats.
> http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/_______________________________________________
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> Virtuoso-users@...
> https://lists.sourceforge.net/lists/listinfo/virtuoso-users
>
>
>