Can I checkpoint and store dynamic tables in Apache Flink into RocksDB as persistent backend? If so can I have 20+ GB here?
Flink SQL will store in the configured state backend (which can be RocksDB) whatever state is needed to satisfy the needs of the query being executed. There's no problem having 20+ GB there. (Some users have 10's of TB.)
But keep in mind that you cannot directly access this state. You will need to send the results of your query to an external sink.