Hi!
We are planning to change the prefix and associated URIs in RDF representation for Wikidata from:
PREFIX wikibase: http://wikiba.se/ontology-beta#
to:
PREFIX wikibase: http://wikiba.se/ontology#
If you are using Wikidata Query Service, you do not have to do anything, as WDQS already is using the new definition.
However, if you consume RDF exports from Wikidata or RDF dumps directly, you will need to change your clients to expect the new URI scheme for Wikibase ontology. Also, if you're using Wikibase extension in your project, please be aware that the RDF URIs generated by it will use this prefix after the change. This is defined in repo/includes/Rdf/RdfVocabulary.php around line 175:
self::NS_ONTOLOGY => self::ONTOLOGY_BASE_URI . "#",
The new data will have schema:softwareVersion "1.0.0" triple on the dataset node[1], which will allow your software to distinguish the new data format from the old one.
The task tracking the change is https://phabricator.wikimedia.org/T112127. I will make another announcement when the change is merged and deployed and the data produced by Wikidata is going to change.
Please contact me (or comment in the task) if you have any questions or concerns.
[1] https://www.mediawiki.org/wiki/Wikibase/Indexing/RDF_Dump_Format#Header