(Feldera co-founder here.) There are some cases where Feldera needs to index data indefinitely, yes. For those cases, Feldera can put those indexes on storage rather than keeping them entirely in RAM.
In a lot of cases where one might initially think that data needs to stay around indefinitely, people actually want the results from the last hour or day or month, etc. For those cases, Feldera supports a concept called "lateness" that allows it to drop older data: https://docs.feldera.com/sql/streaming/#lateness-expressions.
In a lot of cases where one might initially think that data needs to stay around indefinitely, people actually want the results from the last hour or day or month, etc. For those cases, Feldera supports a concept called "lateness" that allows it to drop older data: https://docs.feldera.com/sql/streaming/#lateness-expressions.