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Flink Jira Bot updated FLINK-8566: ---------------------------------- Labels: auto-unassigned stale-major (was: auto-unassigned) I am the [Flink Jira Bot|https://github.com/apache/flink-jira-bot/] and I help the community manage its development. I see this issues has been marked as Major but is unassigned and neither itself nor its Sub-Tasks have been updated for 30 days. I have gone ahead and added a "stale-major" to the issue". If this ticket is a Major, please either assign yourself or give an update. Afterwards, please remove the label or in 7 days the issue will be deprioritized. > Replace retract/insert of same record for state retention timer resets > ---------------------------------------------------------------------- > > Key: FLINK-8566 > URL: https://issues.apache.org/jira/browse/FLINK-8566 > Project: Flink > Issue Type: Improvement > Components: Table SQL / Legacy Planner > Affects Versions: 1.5.0 > Reporter: Fabian Hueske > Priority: Major > Labels: auto-unassigned, stale-major > > Currently a simple query like {{SELECT DISTINCT a, b, c FROM tableX}} is > translated into a plan that generates a retraction stream. However, one would > assume that an append stream should be possible as well. In fact, the plan > doesn't produce actual updates. > Internally, the {{DISTINCT}} is translated into a {{GROUP BY}} with all > distinct fields being keys and no aggregation functions. The corresponding > operator produces updates, because aggregation function might update their > results as new records are received. So we could just implement a dedicated > operator for {{DISTINCT}}. However, this would not work if a user configures > a state retention time. In this case, we emit retraction/insert messages for > the same (distinct) record whenever a new row is received to reset the state > clean-up timers of the downstream operators. > One way to solve this issue to implement a dedicated mechanism to update > state clean-up timers for unchanged records instead of sending out > retraction/insert messages with identical records. This mechanism would just > be used to reset the timers and could also be used for append streams. For > example, we could replace the boolean flag in CRow with a byte that can take > more than two values. -- This message was sent by Atlassian Jira (v8.3.4#803005)