Fremantle
· Wikimedia Commons ·
Exploring structured data on commons, by Bawolff, 28 February 2025:
Copious use of named subqueries (due to them being isolated by the optimizer) can really help here.
If you are fetching distinct terms (or counts of distinct terms) ensuring that blazegraph can use the distinct term optimization is very helpful. It seems like the blazegraph query optimizer isn't very good and often cannot use this optimization even when it should. Making the group by very simple and putting it into a named subquery can help with this.
An interesting post about Structured Data on Commons, and how to query with it. Reminds me that I have been meaning to add support for it to UnlinkedWikibase (although the weird authentication system is perhaps why I haven't bothered so far).
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