Github user dianfu commented on the issue:
https://github.com/apache/flink/pull/5142
@dawidwys @StephanEwen Sorry for late response. For question 1 and 2, I
have the same thought with @dawidwys and have updated the PR accordingly. For
question 3, I think `int` is enough as we currently store `SharedBufferEntry`
in a `HashMap` for each `SharedBufferPage`, and the size of `HashMap` is
`int`. If we want to support `long`, we should also change `HashMap` to
something else. What's your thought?---
