Hi Peter,
I generated the datasets from your python script and loaded them into a local
Virtuoso open source multiple times but did not see any occurrences of the
error:
SQL> select * from load_list;
ll_file
ll_graph
I created some synthetic data that tickles the bug reliably on my machine with
a standard virtuoso.ini (just adding the directory for the files to the
allowed list). I'm attaching the generator program for the files and a
loading script.
peter
On 12/18/18 9:46 AM, Peter F. Patel-Schneider
I did a bit of digging and it sure looks as if there is a race condition in
rdf_rl_lang_id in ttlpv.sql. This code appears to check to see if the
language tag is already in DB.DBA.RDF_LANGUAGE and adds it if not. But
another thread could do the same insert between the check and the insert, as
I'm loading the Turtle Wikidata RDF complete dump, split into pieces and
loaded with 10 active readers. About half the time the load fails with one
or more of these errors. The errors are always near the beginning of the
load---in the first group of 10 files to be loaded and near the beginning
