What is the ShortenLongURIs? Virtuoso configuration parameter
What?
The ShortenLongURIs? parameter is a Virtuoso configuration setting to shorten extremely long URIs in datasets when loading with the RDF Bulk Loader.
Why?
Some RDF datasets have long URIs that exceed the Virtuoso internal maximum size of 1900 bytes and thus need to be shortened to avoid errors like:
SR133: Can not set NULL to not nullable column 'DB.DBA.RDF_QUAD.S' (or .O, or .P)
which has been seen loading some of the DBpedia 3.7 datasets, for example.
How?
The Virtuoso ShortenLongURIs? parameter needs to be set in the [SPARQL] section of the Virtuoso configuration file (virtuoso.ini by default) and restart the Virtuoso Server.
[SPARQL] . . . ShortenLongURIs = 1 . . .
Note: The ShortenLongURIs? parameter is only in the Virtuoso 06.03.3131+ commercial builds, at the time of writing it is not included in the open source 6.1.4 archives but will be in the next 6.1.5 release.
A patch to enable this feature is however available from the Virtuso patches page on source forge, which can be applied to a 6.1.4 archive from source forge and the Virtuoso server binary rebuilt.