I can't really find any examples / docs for Flink's AsyncTableFunction and I have a hard time getting it to work. Is there any example you can share that just takes as input a String key and outputs lets say a record (returned by the lookup?) Also is not clear to me how the async happens internally. Is the future in the eval method signature used?
I tried implementing eval methods like: *public final void eval(CompletableFuture<Collection<RowData>> future, Object... keys)* *or * *public void eval(CompletableFuture<Collection<Row>> result, String rowkey)* but in both cases if I do something like *SELECT asyncfn(accountId) from transactions;* I get *org.apache.calcite.sql.validate.SqlValidatorException: No match found for function signature asyncfn(<CHARACTER>)* Not sure what I am missing Thanks, Giannis
