On 07/09/2021 12:33, Holger Knublauch wrote:
Having said this, I honestly don't think the limitations of one
serialization should be enough to motivate such a drastic change to how
prefixes are managed in TDB.
It is not one serialization - it includes JSON-LD, where it looks like
new work will include packages of graphs as a dataset. It also makes
default union graph work properly and consistently. A dataset is a
logical collection of data - shared prefixes makes sense and is natural
for datasets read/write.
TDB 1 and 2 are both have per-graph prefixes. Hardly drastic.
TQ has its own proprietary graph combination and security layer which is
not based or related to RDF datasets and it does not use Jena data
access security. Using a single dataset to store many graphs of that
graph combination system is local to TQ.
For example it means that if someone
changes the prefixes in one graph of the dataset, then she also changes
the prefixes for all others, even for graphs that are not supposed to be
writable for her. And then what would happen if two graphs are loaded
and added from turtle files where each declares "ex" prefix? All this
sounds very fragile and makes the use of such shared-prefixmapping
datasets rather limiting - the old design was working just fine.
The triples are kept apart. The second prefix does not change the
earlier data.
Andy
