Flink Sql Join, how to clear the sql join state?

[LakeShen]

Hi community，now I am use flink sql inner join in my code,I saw the flink
document, the flink sql inner join will keep both sides of the join input
in Flink’s state forever.
As result , the hdfs files size are so big , is there any way to clear the
sql join state?
Thanks to your reply.