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https://issues.apache.org/jira/browse/HIVE-21133?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jesus Camacho Rodriguez updated HIVE-21133:
-------------------------------------------
Description:
Implement virtual views with rewriting enabled, useful to check whether a
certain rewriting will be triggered. These view definitions will be stored in
the user session, and they will only be used when simulation mode is enabled
and user runs {{explain cbo}} / {{explain cbo extended}}.
{code}
set hive.simulation.enable=true;
create view mv1_n2 enable rewrite as
select * from emps_n3 where empid < 150;
explain cbo
select *
from (select * from emps_n3 where empid < 120) t
join depts_n2 using (deptno);
drop view mv1_n2;
{code}
was:
Implement simulated materialized views, useful to check whether a certain
rewriting will be triggered. Simulated materialized views definitions will be
stored in the user session, and they will only be used when simulation mode is
enabled and user runs {{explain cbo}} / {{explain cbo extended}}.
{code}
set hive.simulation.enable=true;
create simulated materialized view mv1_n2 as
select * from emps_n3 where empid < 150;
explain cbo
select *
from (select * from emps_n3 where empid < 120) t
join depts_n2 using (deptno);
drop simulated materialized view mv1_n2;
{code}
> Support views with rewriting enabled useful for debugging
> ---------------------------------------------------------
>
> Key: HIVE-21133
> URL: https://issues.apache.org/jira/browse/HIVE-21133
> Project: Hive
> Issue Type: Improvement
> Components: Materialized views
> Reporter: Jesus Camacho Rodriguez
> Assignee: Jesus Camacho Rodriguez
> Priority: Major
> Attachments: HIVE-21133.01.patch, HIVE-21133.02.patch,
> HIVE-21133.02.patch, HIVE-21133.patch
>
>
> Implement virtual views with rewriting enabled, useful to check whether a
> certain rewriting will be triggered. These view definitions will be stored in
> the user session, and they will only be used when simulation mode is enabled
> and user runs {{explain cbo}} / {{explain cbo extended}}.
> {code}
> set hive.simulation.enable=true;
> create view mv1_n2 enable rewrite as
> select * from emps_n3 where empid < 150;
> explain cbo
> select *
> from (select * from emps_n3 where empid < 120) t
> join depts_n2 using (deptno);
> drop view mv1_n2;
> {code}
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