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Flink Jira Bot commented on FLINK-5677: --------------------------------------- This major issue is unassigned and itself and all of its Sub-Tasks have not been updated for 30 days. So, it has been labeled "stale-major". If this ticket is indeed "major", please either assign yourself or give an update. Afterwards, please remove the label. In 7 days the issue will be deprioritized. > Validation layer should check whether field can be used as grouping key > ----------------------------------------------------------------------- > > Key: FLINK-5677 > URL: https://issues.apache.org/jira/browse/FLINK-5677 > Project: Flink > Issue Type: Improvement > Components: Table SQL / API > Reporter: Timo Walther > Priority: Major > Labels: stale-major > > When grouping on a GenericType (e.g. {{Object}}). The validation layer does > no checking of types. The {{groupBy/keyBy}} of DataSet/DataStream API throws > the exception. The validation layer should check this before. > {code} > public static class OuterPojo { > public Object object = new Object(); > } > tEnv.sql("SELECT testing.object FROM testing GROUP BY testing.object") > {code} > leads to > {code} > Exception in thread "main" > org.apache.flink.api.common.InvalidProgramException: This type > (GenericType<java.lang.Object>) cannot be used as key. > at > org.apache.flink.api.common.operators.Keys$ExpressionKeys.<init>(Keys.java:270) > at > org.apache.flink.api.common.operators.Keys$ExpressionKeys.<init>(Keys.java:223) > at org.apache.flink.api.java.DataSet.groupBy(DataSet.java:692) > at > org.apache.flink.table.plan.nodes.dataset.DataSetAggregate.translateToPlan(DataSetAggregate.scala:134) > at > org.apache.flink.table.api.BatchTableEnvironment.translate(BatchTableEnvironment.scala:305) > at > org.apache.flink.table.api.BatchTableEnvironment.translate(BatchTableEnvironment.scala:289) > at > org.apache.flink.table.api.java.BatchTableEnvironment.toDataSet(BatchTableEnvironment.scala:146) > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005)