Github user hsuanyi commented on a diff in the pull request:

    https://github.com/apache/drill/pull/407#discussion_r55597867
  
    --- Diff: 
exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/union/UnionAllRecordBatch.java
 ---
    @@ -294,13 +313,41 @@ public UnionAllInput(UnionAllRecordBatch 
unionAllRecordBatch, RecordBatch left,
           rightSide = new OneSideInput(right);
         }
     
    +    private boolean isBothSideEmpty() {
    +      return leftIsFinish && rightIsFinish;
    +    }
    +
         public IterOutcome nextBatch() throws SchemaChangeException {
           if(upstream == RecordBatch.IterOutcome.NOT_YET) {
             IterOutcome iterLeft = leftSide.nextBatch();
             switch(iterLeft) {
               case OK_NEW_SCHEMA:
    -            break;
    +            whileLoop:
    +            while(leftSide.getRecordBatch().getRecordCount() == 0) {
    +              iterLeft = leftSide.nextBatch();
    +
    +              switch(iterLeft) {
    +                case STOP:
    +                case OUT_OF_MEMORY:
    +                  return iterLeft;
    +
    +                case NONE:
    --- End diff --
    
    The while is for the case where the first few batches are empty and then 
union-all receive NONE.
    
    So we need to replicate this logic to right side too.


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---

Reply via email to