Re: [Virtuoso-users] Sparql Nested depth exceed error

[Ivan Mikhailov]

Hello Sachit,

One of solutions is to handle the long list of properties at the client
side:

DESCRIBE ?isbsgProject

could be a fast and simple replacement for

> > SELECT
> > ?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id
> > ?isbsgProject*>isbsg:data_quality_rating
> as ?data_quality_rating
> > ?isbsgProject*>isbsg:ufp_rating as ?ufp_rating
> > 
> > ...
> 


Best Regards,

Ivan Mikhailov
OpenLink Software
http://virtuoso.openlinksw.com


On Mon, 2011-10-03 at 12:49 +1100, Sachit Malhotra wrote:
> Hi Ivan,
> 
> 
> Thanks for the response. I'll see if i can modify the query and get
> less outer joins and see if it fixes the issue.
> 
> 
> Thanks.
> Sachit.
> 
> On Fri, Sep 30, 2011 at 11:05 PM, Ivan Mikhailov
>  wrote:
> Hello Sachit,
> 
> On Wed, 2011-09-28 at 12:12 +1000, Sachit Malhotra wrote:
> > Hi Guys,
> >
> >
> > I am trying to run a query by selecting 240 columns. Here's
> how the
> > query looks like:
> >
> >
> > prefix isbsg:
> >
> 
> 
> > SELECT
> > ?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id
> > ?isbsgProject*>isbsg:data_quality_rating
> as ?data_quality_rating
> > ?isbsgProject*>isbsg:ufp_rating as ?ufp_rating
> > 
> > ...
> > ...
> > 
> > where
> >
> { 
>  
>  ?exampleProject . }

Re: [Virtuoso-users] Sparql Nested depth exceed error

[Sachit Malhotra]

Hi Ivan,

Thanks for the response. I'll see if i can modify the query and get less
outer joins and see if it fixes the issue.

Thanks.
Sachit.

On Fri, Sep 30, 2011 at 11:05 PM, Ivan Mikhailov
wrote:

> Hello Sachit,
>
> On Wed, 2011-09-28 at 12:12 +1000, Sachit Malhotra wrote:
> > Hi Guys,
> >
> >
> > I am trying to run a query by selecting 240 columns. Here's how the
> > query looks like:
> >
> >
> > prefix isbsg:
> > <
> http://localhost:8890/about/id/http/sachit-dev.clearbluewater.com.au:8890/DAV/home/dav/text.csv#
> >
> > SELECT
> > ?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id
> > ?isbsgProject*>isbsg:data_quality_rating as ?data_quality_rating
> > ?isbsgProject*>isbsg:ufp_rating as ?ufp_rating
> > 
> > ...
> > ...
> > 
> > where
> > { 
>  ?exampleProject .
> }
>
> I.e., ~240 LEFT OUTER JOIN-s in the execution plan. That might be
> unrealistic even if ?isbsgProject is bound to a constant (that's not
> evident from the provided fragment of the query).
>
> > There are three issues that i have:
> >
> >
> >   * ISSUE 1: I cannot select all of the columns.
> >   I get a syntax error when i run the query with all columns
> > added. At about 128 column. Virtuoso 37000 Error SP030: SPARQL
> > compiler, line 128: syntax error
> >   Then when i remove all after 128, i get a second error.
> > Error SP031: SPARQL compiler: The nesting depth of subexpressions
> > exceed limits of SPARQL compiler. Then i remove more columns until i
> > get a result. So i got about 57 columns.
>
> *> is a shortcut for an OPTIONAL clause, and SPARQL spec says that
> OPTIONAL is binary operator. So
>
> ?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id
> ?isbsgProject*>isbsg:data_quality_rating as ?data_quality_rating
> ?isbsgProject*>isbsg:ufp_rating as ?ufp_rating
> ...
>
>  results in
>
> ...
>
> { 
>  ?exampleProject .
> }
>  OPTIONAL { ?isbsgProject
> isbsg:isbsg_project_id ?isbsg_project_id } }
>OPTIONAL { ?isbsgProject isbsg:data_quality_rating ?data_quality } }
>   OPTIONAL { ?isbsgProject isbsg:ufp_rating ?ufp_rating } }
> ... }
>
> with nesting equal to number of distinct "*>" (plus a small constant)
>
>
> >   * ISSUE 2: (This has been raised earlier as well). When i add a
> > from, again, the number of columns decreases from 57. So the
> > more i add, the less column i can select.
>
> It's a separate issue, minor if compared with issues above.
>
> >   * ISSUE 3: Query execution time. Virtuoso 42000 Error The
> > estimated execution time 1779716608 (sec) exceeds the limit of
> > 2147483647 (sec).I increased the execution time to test but
> > the estimated time isn't even greater than the limit and still
> > i get the above error.
>
> That may demonstrate the issue with error report, that is unable to
> properly print the number that exceeds MAXINT. Actually, the actual
> value of execution time forecast could be tens of orders of magnitude
> greater than MAXINT or the age of Universe.
>
> Best Regards,
>
> Ivan Mikhailov
> OpenLink Software
> http://virtuoso.openlinksw.com
>
>
>
>


-- 

Sachit Malhotra | Clear Blue Water Pty Ltd
+61 403565478 | smalho...@clearbluewater.com.au

Re: [Virtuoso-users] Sparql Nested depth exceed error

[Ivan Mikhailov]

Hello Sachit,

On Wed, 2011-09-28 at 12:12 +1000, Sachit Malhotra wrote:
> Hi Guys,
> 
> 
> I am trying to run a query by selecting 240 columns. Here's how the
> query looks like:
> 
> 
> prefix isbsg:
> 
> SELECT 
> ?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id 
> ?isbsgProject*>isbsg:data_quality_rating as ?data_quality_rating 
> ?isbsgProject*>isbsg:ufp_rating as ?ufp_rating 
> 
> ...
> ...
> 
> where
> {  
>  ?exampleProject . }

I.e., ~240 LEFT OUTER JOIN-s in the execution plan. That might be
unrealistic even if ?isbsgProject is bound to a constant (that's not
evident from the provided fragment of the query).

> There are three issues that i have:
> 
> 
>   * ISSUE 1: I cannot select all of the columns.  
>   I get a syntax error when i run the query with all columns
> added. At about 128 column. Virtuoso 37000 Error SP030: SPARQL
> compiler, line 128: syntax error
>   Then when i remove all after 128, i get a second error.
> Error SP031: SPARQL compiler: The nesting depth of subexpressions
> exceed limits of SPARQL compiler. Then i remove more columns until i
> get a result. So i got about 57 columns.

*> is a shortcut for an OPTIONAL clause, and SPARQL spec says that
OPTIONAL is binary operator. So

?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id 
?isbsgProject*>isbsg:data_quality_rating as ?data_quality_rating 
?isbsgProject*>isbsg:ufp_rating as ?ufp_rating 
...

 results in

...

{ 
 ?exampleProject . }
 OPTIONAL { ?isbsgProject
isbsg:isbsg_project_id ?isbsg_project_id } }
OPTIONAL { ?isbsgProject isbsg:data_quality_rating ?data_quality } }
   OPTIONAL { ?isbsgProject isbsg:ufp_rating ?ufp_rating } }
... }

with nesting equal to number of distinct "*>" (plus a small constant)


>   * ISSUE 2: (This has been raised earlier as well). When i add a
> from, again, the number of columns decreases from 57. So the
> more i add, the less column i can select.

It's a separate issue, minor if compared with issues above.

>   * ISSUE 3: Query execution time. Virtuoso 42000 Error The
> estimated execution time 1779716608 (sec) exceeds the limit of
> 2147483647 (sec).I increased the execution time to test but
> the estimated time isn't even greater than the limit and still
> i get the above error. 

That may demonstrate the issue with error report, that is unable to
properly print the number that exceeds MAXINT. Actually, the actual
value of execution time forecast could be tens of orders of magnitude
greater than MAXINT or the age of Universe.

Best Regards,

Ivan Mikhailov
OpenLink Software
http://virtuoso.openlinksw.com

[Virtuoso-users] Sparql Nested depth exceed error

[Sachit Malhotra]

Hi Guys,

I am trying to run a query by selecting 240 columns. Here's how the query
looks like:

prefix isbsg: <
http://localhost:8890/about/id/http/sachit-dev.clearbluewater.com.au:8890/DAV/home/dav/text.csv#
>
SELECT
?isbsgProject*>isbsg:isbsg_project_id as ?isbsg_project_id
?isbsgProject*>isbsg:data_quality_rating as ?data_quality_rating
?isbsgProject*>isbsg:ufp_rating as ?ufp_rating

...
...

where { 
 ?exampleProject . }

There are three issues that i have:


   - *ISSUE 1: *I cannot select all of the columns. * *

  I get a syntax error when i run the query with all columns added.
At about 128 column. Virtuoso 37000 Error SP030: SPARQL compiler, line 128:
syntax error
  Then when i remove all after 128, i get a second error. Error
SP031: SPARQL compiler: The nesting depth of subexpressions exceed limits of
SPARQL compiler. Then i remove more columns until i get a result. So i got
about 57 columns.


   - *ISSUE 2: *(This has been raised earlier as well)*. *When i add a from,
   again, the number of columns decreases from 57. So the more i add, the less
   column i can select.



   - *ISSUE 3: *Query execution time. Virtuoso 42000 Error The estimated
   execution time 1779716608 (sec) exceeds the limit of 2147483647 (sec).I
   increased the execution time to test but the estimated time isn't even
   greater than the limit and still i get the above error. * *

Am i doing something fundamentally wrong or has this been experienced
by others as well ?? Is there a  work around for this ?? Any help is much
appreciated.

Thanks.

-- 

Sachit Malhotra | Clear Blue Water Pty Ltd
+61 403565478 | smalho...@clearbluewater.com.au