Hello Everyone 
,
As I'm working on a project that requires building up virtual graphs and running federated queries, I'm quite new to utilising Stardog. I've read through the rudimentary guides and documentation, but I still need your assistance with a few things.
In order to establish a virtual graph, I'm first attempting to link Stardog to an external relational database (PostgreSQL). I've tried all the steps listed in the instructions, but I still keep getting connection issues. Is there anyone who could offer a thorough tutorial or advice on how to resolve typical connectivity problems?
Second, I have to do federated searches across several data sources, such as the virtual graph discussed earlier and additional RDF datasets kept in Stardog.
I'm not sure how to set up these queries to get the best performance and reliable responses. I would be very grateful for any best practices or examples of intricate federated queries.
Finally, if you know of any more materials, webinars, or community discussions that could assist someone like me who is just starting out with these features, please let me know.
I also check this: https://groups.google.com/a/stardog.com/g/stardog/sap/c/_0hltyHnng8
Thank you 
in advance for your ssistance.