On 1/5/15 1:33 PM, Jörn Hees wrote:
Hi,TLDR: i'm trying to get node degree counts and neighbourhood subgraphs for a lot of nodes from a local virtuoso-opensource endpoint. My problem is that i seem to get partial / wrong results (similar to https://github.com/openlink/virtuoso-opensource/issues/112 ). Now as this is a local endpoint i'd like to ask if there is any way i can configure it to only return complete results. If not: Which of the virtuoso.ini settings allow me to reduce the problem? Also: is the ResultSetMaxRows parameter applied before aggregation in the counts? Details: We have a local Virtuoso endpoint set up as described here: https://joernhees.de/blog/2014/11/10/setting-up-a-local-dbpedia-2014-mirror-with-virtuoso-7-1-0/ configured with: ResultSetMaxRows = 1000000 MaxQueryCostEstimationTime = 600 ; in seconds MaxQueryExecutionTime = 1200 ; in seconds I first run queries like these to get node degrees: SELECT ?node count(*) as ?degree WHERE { { ?node ?p ?o . } UNION { ?s ?p ?node . } VALUES (?node) { %(nodes)s } } I do this in chunks of up to n nodes at once in order to cut down the number of queries i'm doing. (At the moment n = 32, but i'd like to increase it to ~ 1024 if this works somehow.) Depending on the degree counts of the nodes some of them might be expanded (if they're not too big) and this is where my problem starts: skos:Concept is reported to have a ?degree = 4, so it's expanded... Turns out i have 4 triples of the form { skos:Concept ?p ?o } but 1396211 [1] of the form { ?s ?p skos:Concept }. Unlike mentioned in https://github.com/openlink/virtuoso-opensource/issues/112 there is no HTTP header like X-SQL-State: S1TAT in the original count responses indicating anything went wrong ;( If ResultSetMaxRows was somehow applied before aggregation, how did i get 1396211 as a result for "select count(*) where { ?s ?p skos:Concept }" ?
Ensure you query timeout is large enough. Or set the timeout to 0.
As a control mechanism for comparison, using iSQL, you can execute:
sparql
select count(*) where { ?s ?p skos:Concept } ;
Is there a maximum value for ResultSetMaxRows?
2 Million.
Also are there any other settings which could be the reason for these partial results?
No.
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