I had never heard of SPARQL, it appears to be an RDF/triplestore language. This is really great -- it means that you can now execute graph-based queries against Calcite's adapters!
>From brief googling, it seems there are implementations of SPARQL that run on top of major DB's like Postgres/MySQL. So this could be used with the JDBC adapter then I assume? > "I have also planned to share some notes on the process of creating an adapter from scratch, since there are many moving parts (and I may have missed or misunderstood several)." This would be great, you appear to have a better understanding of the pieces of Calcite and have implemented a lot more custom behavior. Would love to read a walkthrough/explainer or guide and it would likely be invaluable to others. On Sun, Jan 23, 2022 at 5:45 PM Nicola Vitucci <[email protected]> wrote: > Hi all, > > I have been dabbling with Calcite for a while out of interest and curiosity > and, in order to become more familiar with the code and the overall > architecture, I've tried implementing an adapter [1] to run SQL queries > over SPARQL endpoints. As Gavin has done, I have also planned to share some > notes on the process of creating an adapter from scratch, since there are > many moving parts (and I may have missed or misunderstood several). > > The project is at an early stage and can be improved in many ways, but, as > I am still learning about Calcite itself, I thought it would make sense to > share the work in progress with the community and ask for some feedback > (plus, it's easier to ask for help when there is something concrete > already). The rules are still relatively basic (e.g. neither joins nor > aggregations are pushed down to SPARQL as of now); in the meantime, I am > trying to come up with as many tests as I can to make sure that everything > works (and keeps working) as expected. > > On the "usefulness" side, it is true that trying to force a table view on > graph data is always going to be a challenge, and there are many approaches > to it - but I think this could be a good starting point for use cases such > as data exploration, analytics, etc. > > Thank you all for the great work on Calcite, and please do share your > thoughts and comments! > > Nicola > > [1] https://github.com/nvitucci/calcite-sparql >
