Flink SQL is quite limited compared to Feldera/DBSP or Frank’s Materialize.com, and has some correctness limitations: it’s “eventually consistent” but until you stop the data it’s unlikely to ever be actually correct when working with streaming joins. https://www.scattered-thoughts.net/writing/internal-consiste...

Not true.

There has to be some change in the code, and they will not share the same semantics (and perhaps won't work when retractions/deletions also appear whilst streaming). And let's not even get to the leaky abstractions for good performance (watermarks et al).