[jira] [Updated] (HIVE-26524) Use Calcite to remove sections of a query plan known never produces rows

["Krisztian Kasa (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-26524?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Krisztian Kasa updated HIVE-26524:
----------------------------------
    Description: 
Calcite has a set of rules to remove sections of a query plan known never produces any rows. In some cases the whole plan can be removed. Such plans are represented with a single {{Values}} operators with no tuples. ex.:
{code:java}
select y + 1 from (select a1 y, b1 z from t1 where b1 > 10) q WHERE 1=0
{code}
{code:java}
HiveValues(tuples=[[]])
{code}
Other cases when plan has outer join or set operators some branches can be replaced with empty values moving forward in some cases the join/set operator can be removed
{code:java}
select a2, b2 from t2 where 1=0
union
select a1, b1 from t1
{code}
{code:java}
HiveAggregate(group=[{0, 1}])
  HiveTableScan(table=[[default, t1]], table:alias=[t1])
{code}

  was:
Calcite has a set of rules to remove sections of a query plan known never produces any rows. In some cases the whole plan can be removed. Such plans are represented with a single {{Values}} operators with no tuples.  ex.:
{code}
select y + 1 from (select a1 y, b1 z from t1 where b1 > 10) q WHERE 1=0
{code}
{code}
HiveValues(tuples=[[]])
{code}

Other cases when plan has outer join or set operators some branches can be replaced with empty values moving forward the join/set operator can be removed
{code}
select a2, b2 from t2 where 1=0
union
select a1, b1 from t1
{code}

{code}
HiveAggregate(group=[{0, 1}])
  HiveTableScan(table=[[default, t1]], table:alias=[t1])
{code}


> Use Calcite to remove sections of a query plan known never produces rows
> ------------------------------------------------------------------------
>
>                 Key: HIVE-26524
>                 URL: https://issues.apache.org/jira/browse/HIVE-26524
>             Project: Hive
>          Issue Type: Improvement
>          Components: CBO
>            Reporter: Krisztian Kasa
>            Assignee: Krisztian Kasa
>            Priority: Major
>
> Calcite has a set of rules to remove sections of a query plan known never produces any rows. In some cases the whole plan can be removed. Such plans are represented with a single {{Values}} operators with no tuples. ex.:
> {code:java}
> select y + 1 from (select a1 y, b1 z from t1 where b1 > 10) q WHERE 1=0
> {code}
> {code:java}
> HiveValues(tuples=[[]])
> {code}
> Other cases when plan has outer join or set operators some branches can be replaced with empty values moving forward in some cases the join/set operator can be removed
> {code:java}
> select a2, b2 from t2 where 1=0
> union
> select a1, b1 from t1
> {code}
> {code:java}
> HiveAggregate(group=[{0, 1}])
>   HiveTableScan(table=[[default, t1]], table:alias=[t1])
> {code}



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