What kind of expectation do you have after you add the "max(a)" aggregation:
a. Keep summing a and start to calculate max(a) after you added. In other words, max(a) won't take the history data into account. b. First process all the historical data to get a result of max(a), and then start to compute sum(a) and max(a) together for the real-time data. Best, Kurt On Tue, Jun 8, 2021 at 2:11 PM JING ZHANG <beyond1...@gmail.com> wrote: > Hi aitozi, > This is a popular demand that many users mentioned, which appears in user > mail list for several times. > Unfortunately, it is not supported by Flink SQL yet, maybe would be solved > in the future. BTW, a few company try to solve the problem in some > specified user cases on their internal Flink version[2]. > Currently, you may try use `State Processor API`[1] as temporary solution. > 1. Do a savepoint > 2. Generates updated the savepoint based on State Processor API > 3. Recover from the new savepoint. > > [1] > https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/libs/state_processor_api/ > [2] https://developer.aliyun.com/article/781455 > > Best regards, > JING ZHANG > > aitozi <gjying1...@gmail.com> 于2021年6月8日周二 下午1:54写道： > >> When use flink sql, we encounter a big problem to deal with sql state >> compatibility. Think we have a group agg sql like ```sql select sum(`a`) >> from source_t group by `uid` ``` But if i want to add a new agg column to >> ```sql select sum(`a`), max(`a`) from source_t group by `uid` ``` Then sql >> state will not be compatible. Is there any on-going work/thoughts to >> improve this situation? >> ------------------------------ >> Sent from the Apache Flink User Mailing List archive. mailing list >> archive >> <http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/> >> at Nabble.com. >> >
