[jira] [Created] (IMPALA-11036) CTAS throw AnalysisException Duplicate column name when subquery contains same query without alias

[Sheng Wang (Jira)]

Sheng Wang created IMPALA-11036:
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             Summary: CTAS throw AnalysisException Duplicate column name when 
subquery contains same query without alias
                 Key: IMPALA-11036
                 URL: https://issues.apache.org/jira/browse/IMPALA-11036
             Project: IMPALA
          Issue Type: Question
            Reporter: Sheng Wang


Hi, recently I found that CTAS will throw AnalysisException Duplicate column 
name when subquery contains same query without alias like this:

{code:java}
create table t3 as select * from (select ds,c1 from t1 ) t1 join (select ds,c2 
from t2 ) t2 on t1.ds=t2.ds;
{code}
Even if we use 't1.ds' and 't2.ds', also same exception, unless we use alias in 
subquery, such as 'ds as t1_ds' and 'ds as t2_ds'. The main reason is when get 
'colLabels_' in SelectStmt, Impala get column label like this: 

{code:java}
  public String toColumnLabel(int selectListPos, boolean useHiveColLabels) {
    if (alias_ != null) return alias_.toLowerCase();
    if (expr_ instanceof SlotRef) {
      SlotRef slotRef = (SlotRef) expr_;
      return Joiner.on(".").join(slotRef.getResolvedPath().getRawPath());
    }
    ......
{code}





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