Query error on `select $segmentName, * from table limit 1`

While running some adhoc queries to debug some things, I found the following query would fail. It’s not a significant issue, because a query explicitly listing columns to select works fine.

select $segmentName, * from table limit 1

with the exception(s)

[
  {
    "errorCode": 200,
    "message": "QueryExecutionError:\njava.lang.RuntimeException: Caught exception while running CombinePlanNode.\n\tat org.apache.pinot.core.plan.CombinePlanNode.run(CombinePlanNode.java:146)\n\tat org.apache.pinot.core.plan.InstanceResponsePlanNode.run(InstanceResponsePlanNode.java:41)\n\tat org.apache.pinot.core.plan.GlobalPlanImplV0.execute(GlobalPlanImplV0.java:45)\n\tat org.apache.pinot.core.query.executor.ServerQueryExecutorV1Impl.processQuery(ServerQueryExecutorV1Impl.java:302)\n...\nCaused by: java.util.concurrent.ExecutionException: java.lang.NullPointerException\n\tat java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122)\n\tat java.base/java.util.concurrent.FutureTask.get(FutureTask.java:205)\n\tat org.apache.pinot.core.plan.CombinePlanNode.run(CombinePlanNode.java:135)\n\t... 15 more\n...\nCaused by: java.lang.NullPointerException"
  }
]

Note, the commit this was on is roughly ce9fb572d157d82f8a014624152ddd53332372be, and I have not yet tried to reproduce this on the latest version.

[suddendust]

This can be closed as it’s released in 0.10.0 @Jackie-Jiang

[Jackie-Jiang]

@suddendust Thanks for volunteering on this. I’ve assigned the issue to you

For the questions:

1. I think the standard SQL behavior returns each column only once
2. We should not return the virtual columns, unless it is explicitly queried, e.g. select $docId, * from ...