Launching multiple SPARQL queries for same API operation

[ivanhb]

Since some triplestores have limitations on SPARQL query length, a practical solution involves splitting long queries and merging the results.

Here's an example:

Consider the following SPARQL query in the API configuration file:

#sparql PREFIX cito: <http://purl.org/spar/cito/>
SELECT (count(?cited) as ?count)
WHERE {
VALUES ?val { [[id]] } .
?oci cito:hasCitingEntity ?val .
?oci cito:hasCitedEntity ?cited .
}

If [[id]] contains many values, the query might exceed the triplestore's limit. To address this, we can run the same query multiple times, each with a smaller subset of values from [[id]]. Finally, we merge the partial results to obtain the complete answer.