[jira] [Work logged] (HIVE-15757) Allow EXISTS/NOT EXISTS correlated subquery with aggregates

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-15757?focusedWorklogId=561420&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-561420 ]

ASF GitHub Bot logged work on HIVE-15757:
-----------------------------------------

                Author: ASF GitHub Bot
            Created on: 05/Mar/21 14:16
            Start Date: 05/Mar/21 14:16
    Worklog Time Spent: 10m 
      Work Description: kasakrisz opened a new pull request #2039:
URL: https://github.com/apache/hive/pull/2039


   ### What changes were proposed in this pull request?
   1. When transforming subquery AST to calcite plan check whether the subquery is a full aggregation: has aggregate functions without group by clause
   2. When building subquery expression return `true` literal if subquery is a full aggregation having `EXISTS` operator instead of `RexSubQuery`
   
   ### Why are the changes needed?
   To support queries like:
   ```
   SELECT t1.bigint_col
   FROM alltypestiny t1
   WHERE EXISTS
     (SELECT SUM(smallint_col) AS int_col
      FROM alltypestiny
      WHERE t1.date_string_col = string_col AND t1.timestamp_col = timestamp_col)
   GROUP BY t1.bigint_col
   ```
   
   ### Does this PR introduce _any_ user-facing change?
   Yes. Current Hive implementation throws exception when compiling queries like the example above. With this patch query compiles and runs.
   
   ### How was this patch tested?
   ```
   mvn test -Dtest.output.overwrite -DskipSparkTests -Dtest=TestMiniLlapLocalCliDriver -Dqfile=subquery_full_aggregate.q -pl itests/qtest -Pitests
   ```


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Issue Time Tracking
-------------------

            Worklog Id:     (was: 561420)
    Remaining Estimate: 0h
            Time Spent: 10m

> Allow EXISTS/NOT EXISTS correlated subquery with aggregates
> -----------------------------------------------------------
>
>                 Key: HIVE-15757
>                 URL: https://issues.apache.org/jira/browse/HIVE-15757
>             Project: Hive
>          Issue Type: Sub-task
>          Components: Query Planning
>            Reporter: Vineet Garg
>            Assignee: Krisztian Kasa
>            Priority: Major
>              Labels: sub-query
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> Currently HIVE doesn't allow correlated EXISTS/NOT EXISTS subqueries which has aggregate without group by e.g.
> {code} select *
> from src b 
> where exists 
>   (select count(*) 
>   from src a 
>   where b.value = a.value  and a.key = b.key and a.value > 'val_9'
>   ) ;
> {code}
> Such queries could be rewritten to replace EXISTS/NOT EXISTS predicate with {{true}} or {{false}} based on aggregate.



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