Smile created FLINK-19592:
-----------------------------

             Summary: MiniBatchGroupAggFunction should emit messages to prevent 
too early state eviction of downstream operators
                 Key: FLINK-19592
                 URL: https://issues.apache.org/jira/browse/FLINK-19592
             Project: Flink
          Issue Type: Bug
          Components: Table SQL / Runtime
    Affects Versions: 1.12.0
            Reporter: Smile


Currently, 
[GroupAggFunction|https://github.com/apache/flink/blob/master/flink-table/flink-table-runtime-blink/src/main/java/org/apache/flink/table/runtime/operators/aggregate/GroupAggFunction.java#L183]
 will emit a retract and a new insert message when a new message with the same 
key arrives. According to 
[Flink-8566|https://issues.apache.org/jira/browse/FLINK-8566], it's a feature 
to prevent too early state eviction of downstream operators.

However, 
[MiniBatchGroupAggFunction|https://github.com/apache/flink/blob/master/flink-table/flink-table-runtime-blink/src/main/java/org/apache/flink/table/runtime/operators/aggregate/MiniBatchGroupAggFunction.java#L206]
 doesn't. Before [Flink-8566|https://issues.apache.org/jira/browse/FLINK-8566] 
being resolved, it should also emit these messages.

*GroupAggFunction.java:*
{code:java}
if (!stateCleaningEnabled && equaliser.equals(prevAggValue, newAggValue)) {
        // newRow is the same as before and state cleaning is not enabled.
        // We do not emit retraction and acc message.
        // If state cleaning is enabled, we have to emit messages to prevent 
too early
        // state eviction of downstream operators.
        return;
} else {
        // retract previous result
        if (generateUpdateBefore) {
                // prepare UPDATE_BEFORE message for previous row
                resultRow.replace(currentKey, 
prevAggValue).setRowKind(RowKind.UPDATE_BEFORE);
                out.collect(resultRow);
        }
        // prepare UPDATE_AFTER message for new row
        resultRow.replace(currentKey, 
newAggValue).setRowKind(RowKind.UPDATE_AFTER);
}
{code}
*MiniBatchGroupAggFunction.java:*

 
{code:java}
if (!equaliser.equals(prevAggValue, newAggValue)) {
        // new row is not same with prev row
        if (generateUpdateBefore) {
                // prepare UPDATE_BEFORE message for previous row
                resultRow.replace(currentKey, 
prevAggValue).setRowKind(RowKind.UPDATE_BEFORE);
                out.collect(resultRow);
        }
        // prepare UPDATE_AFTER message for new row
        resultRow.replace(currentKey, 
newAggValue).setRowKind(RowKind.UPDATE_AFTER);
        out.collect(resultRow);
}
// new row is same with prev row, no need to output
{code}
 

 

 

 



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