Hi Sean AFAIK, Flink does not support SortedMapState currently, there was an issue FLINK-6219 about sorted mapstate before. I think you can reach to this issue if you want sorted mapstate. Sorted MapState for RocksDB can be challenging for Java-based comparator, RocksDB supports the bytes-comparator only.
Best, Congxian Sean Z <xingha...@gmail.com> 于2020年7月24日周五 上午3:36写道： > Hi Flink Community, > > I'm new to this community but have been using Flink for a year or so. As a > user, my team built stuff upon Flink stateful stream processing. We used to > have a use case that we need a sorted map data structure to store our > state, something like TreeMap in Java, to query higher/lower keys, do range > queries, and etc. However, currently, we only have a MapState interface in > Flink. We found RocksDB is kind of sorted storage in nature. To achieve > our use case, we have to do some hacky tricks to bypass current limitations > and use lower RocksDB features as a workaround to implement our own > SortedMapState. I assume that there should be lots of other users who have > the same use case, so I have a few questions here. > > 1. Do we have a feature like SortedMapState already in place, in > development or in the future roadmap? > > 2. If not, could that be a good feature to have? and are there any other > concerns? > > Just want to start a discussion here from a user perspective. If everything > goes well, we are also interested in contributing back to the community. > > > Best regards, > Sean >
