Hello all, We recently noticed in a TDB2 dataset that negative float values (including "negative zero") are corrupted. The batch loader shows a WARN message -- see below. The following simple steps reproduce the problem. This is with Jena 3.10, though the issue seems to exist prior to that.
$ echo "<s> <p> \"-1.0\"^^<http://www.w3.org/2001/XMLSchema#float> ." > test.nt $ tdb2.tdbloader --loc test_tdb2 test.nt 11:07:36 WARN NodeId :: Type set in long: type=Float value=FFFFFFFFBF800000 $ tdb2.tdbquery --loc test_tdb2 "select ?o (datatype(?o) as ?dt) where { ?s ?p ?o }" ---------------------------------------------------------------------- | o | dt | ====================================================================== | 3.1861834394748298E-58 | <http://www.w3.org/2001/XMLSchema#double> | ---------------------------------------------------------------------- TDB1 is OK: $ tdbloader --loc test test.nt 11:09:12 INFO loader :: -- Start triples data phase 11:09:12 INFO loader :: ** Load empty triples table 11:09:12 INFO loader :: -- Start quads data phase 11:09:12 INFO loader :: ** Load empty quads table 11:09:13 INFO loader :: Load: test.nt -- 2019/02/19 11:09:13 PST 11:09:13 INFO loader :: -- Finish triples data phase 11:09:13 INFO loader :: ** Data: 1 triples loaded in 0.11 seconds [Rate: 9.09 per second] 11:09:13 INFO loader :: -- Finish quads data phase 11:09:13 INFO loader :: -- Start triples index phase 11:09:13 INFO loader :: ** Index SPO->POS: 1 slots indexed 11:09:13 INFO loader :: ** Index SPO->OSP: 1 slots indexed 11:09:13 INFO loader :: -- Finish triples index phase 11:09:13 INFO loader :: ** 1 triples indexed in 0.01 seconds [Rate: 166.67 per second] 11:09:13 INFO loader :: -- Finish triples load 11:09:13 INFO loader :: ** Completed: 1 triples loaded in 0.12 seconds [Rate: 8.26 per second] 11:09:13 INFO loader :: -- Finish quads load $ tdbquery --loc test "select ?o (datatype(?o) as ?dt) where { ?s ?p ?o }" ----------------------------------------------------------------------------------------------- | o | dt | =============================================================================================== | "-1.0"^^<http://www.w3.org/2001/XMLSchema#float> | < http://www.w3.org/2001/XMLSchema#float> | ----------------------------------------------------------------------------------------------- Creating the dataset via fuseki shows a similar pattern: "in-memory" and "persistent" correctly retrieve the float value, but "persistent (tdb2)" returns a corrupt value interpreted as a double. Is this a known issue / limitation of TDB2? If so, are there any suggested workarounds other than always using doubles, at least for negatives? Thanks, - Mike For completeness, this is the result of storing -1.0, -0.0, 0.0, and 1.0 as both float and double (8 values total). The combination of float + negative results in the 2 near-zero "double" values. ----------------------------------------------------------------------------------------------- | o | dt | =============================================================================================== | "0.0"^^<http://www.w3.org/2001/XMLSchema#float> | < http://www.w3.org/2001/XMLSchema#float> | | "1.0"^^<http://www.w3.org/2001/XMLSchema#float> | < http://www.w3.org/2001/XMLSchema#float> | | 0.0e0 | < http://www.w3.org/2001/XMLSchema#double> | | 3.186183062619485E-58 | < http://www.w3.org/2001/XMLSchema#double> | | 3.1861834394748298E-58 | < http://www.w3.org/2001/XMLSchema#double> | | 1.0e0 | < http://www.w3.org/2001/XMLSchema#double> | | -0.0e0 | < http://www.w3.org/2001/XMLSchema#double> | | -1.0e0 | < http://www.w3.org/2001/XMLSchema#double> | -----------------------------------------------------------------------------------------------
