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Jark Wu commented on FLINK-23544: --------------------------------- I guess the reason maybe PARTITIONED BY clause of TVF syntax is not supported in Calcite parser. If we want to support syntax mentioned in FLIP, we need to wait for CALCITE-4337, but this ticket doesn't have much progress in Calcite community and this means it may takes long to deliver SESSION Window TVF feature for Flink users. But I agree [~twalthr] the API must be consistent with FLIP, otherwise, there should be another public discussion, and we need to come up with a solution for API compatibility/migration. > Window TVF Supports session window > ---------------------------------- > > Key: FLINK-23544 > URL: https://issues.apache.org/jira/browse/FLINK-23544 > Project: Flink > Issue Type: Sub-task > Components: Table SQL / Planner > Reporter: JING ZHANG > Assignee: JING ZHANG > Priority: Minor > Labels: pull-request-available > Fix For: 1.14.0 > > > Window TVF would support SESSION window in the following case: > # SESSION Window TVF followed by Window Aggregate, in this case SESSION > window TVF would be pulled up into WindowAggregate, so Window assigner would > happen in WindowAggrgeate > > *Note, SESSION window TVF only works in limited cases currently, the > following user cases is not supported yet:* > # *SESSION WINDOW TVF followed by Window JOIN* > # *SESSION WINDOW TVF followed by Window RANK*** > *BESIDES, SESSION window Aggregate does not support the following performance > improvement yet:* > 1. Split Distinct Aggregation > 2. Local-global Aggregation > 3. Mini-batch Aggregate -- This message was sent by Atlassian Jira (v8.3.4#803005)