[Mulgara-dev] Blank Nodes

[Paul Gearon]

On Aug 3, 2007, at 2:51 AM, Life is hard, and then you die wrote:

> On Thu, Aug 02, 2007 at 12:57:32PM -0400, David Moll wrote:
>>
>> We have an interesting issue where some how we have roughly 30,000  
>> blank
>> nodes in the system, blank nodes we did not insert on purpose but
>> appeared after we had a hard shutdown and then brought Mulgara  
>> back up.
>> As an example if I run a query in the web ui I get the following
>> response
>
> Uh oh, it sounds like you ran into the same problem we did about half
> a year ago - see the "corrupted string-pool?" thread last February.

That's why I asked which version he was running.  I believe we fixed  
that problem.... didn't we?  (you never told me if we didn't!)

> [snip]
>> Does anyone know of method where we could query the blank nodes  
>> directly
>> and then delete them?
>
> I think you should be able to use the nodetyping model (see under
> advanced iTQL operations) for this - something along the lines of
>
>   select $s from ... where $s $p $o minus
>       ($s <rdf:type> <rdfs:Literal> in <...#type> or $s <rdf:type>  
> <mulgara:uriReference> in <...#type>)

Hah!  I beat you to the punch on this one!  :-)

/me feels good about this.... after all, I *wrote* the nodetyping  
model  :-)  (though looking at it, I'd have done a few things  
differently.  Still, it works)

Paul