Thanks for your response, Benchao. Here is my thought on the newly added option. Users' current jobs are running on a version without minibatch join. If the existing option to enable minibatch join is utilized, then when users' jobs are migrated to the new version, the internal behavior of the join operation within the jobs will change. Although the semantic of changelog emitted by the Join operator is eventual consistency, the change might not be supposed for the downstream of the job which requires details of changelog. This newly added option also refers to 'table.exec.deduplicate.mini-batch.compact-changes-enabled'.
As for the implementation，The new operator shares the state of the original operator and it merely has an additional minibatch for storing records to do some optimization. The storage remains consistent, and there is minor modification to the computational logic. Best, Xu Shuai > 2024年1月10日 22:56，Benchao Li <libenc...@apache.org> 写道： > > Thanks shuai for driving this, mini-batch Join is a very useful > optimization, +1 for the general idea. > > Regarding the configuration > "table.exec.stream.join.mini-batch-enabled", I'm not sure it's really > necessary. The semantic of changelog emitted by the Join operator is > eventual consistency, so there is no much difference between original > Join and mini-batch Join from this aspect. Besides, introducing more > options would make it more complex for users, harder to understand and > maintain, which we should be careful about. > > One thing about the implementation, could you make the new operator > share the same state definition with the original one? > > shuai xu <xushuai...@gmail.com> 于2024年1月10日周三 21:23写道： >> >> Hi devs, >> >> I’d like to start a discussion on FLIP-415: Introduce a new join operator to >> support minibatch[1]. >> >> Currently, when performing cascading connections in Flink, there is a pain >> point of record amplification. Every record join operator receives would >> trigger join process. However, if records of +I and -D matches , they could >> be folded to reduce two times of join process. Besides, records of -U +U >> might output 4 records in which two records are redundant when encountering >> outer join . >> >> To address this issue, this FLIP introduces a new >> MiniBatchStreamingJoinOperator to achieve batch processing which could >> reduce number of outputting redundant messages and avoid unnecessary join >> processes. >> A new option is added to control the operator to avoid influencing existing >> jobs. >> >> Please find more details in the FLIP wiki document [1]. Looking >> forward to your feedback. >> >> [1] >> https://cwiki.apache.org/confluence/display/FLINK/FLIP-415%3A+Introduce+a+new+join+operator+to+support+minibatch >> >> Best, >> Xu Shuai > > > > -- > > Best, > Benchao Li
