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Posted to issues@hive.apache.org by "comet (Jira)" <ji...@apache.org> on 2022/09/07 10:56:00 UTC

[jira] [Comment Edited] (HIVE-20006) Make materializations invalidation cache work with multiple active remote metastores

    [ https://issues.apache.org/jira/browse/HIVE-20006?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17601241#comment-17601241 ] 

comet edited comment on HIVE-20006 at 9/7/22 10:55 AM:
-------------------------------------------------------

apology, is MaterializationsCacheCleanerTask is replaced with another class on Hive 3.1 onward?  I would like to set below property, but class not found

 

 

 <property>
          <name>metastore.task.threads.always</name>
          <value>org.apache.hadoop.hive.metastore.events.EventCleanerTask,org.apache.hadoop.hive.metastore.MaterializationsCacheCleanerTask</value>
</property>

 


was (Author: JIRAUSER295079):
apology, is MaterializationsCacheCleanerTask is replaced with another class on Hive 3.1 onward?  I would like to set below property, but class not found

 

```

 <property>
          <name>metastore.task.threads.always</name>
          <value>org.apache.hadoop.hive.metastore.events.EventCleanerTask,org.apache.hadoop.hive.metastore.MaterializationsCacheCleanerTask</value>
</property>

 

```

> Make materializations invalidation cache work with multiple active remote metastores
> ------------------------------------------------------------------------------------
>
>                 Key: HIVE-20006
>                 URL: https://issues.apache.org/jira/browse/HIVE-20006
>             Project: Hive
>          Issue Type: Improvement
>          Components: Materialized views
>    Affects Versions: 3.0.0
>            Reporter: Jesus Camacho Rodriguez
>            Assignee: Jesus Camacho Rodriguez
>            Priority: Critical
>             Fix For: 4.0.0, 4.0.0-alpha-1
>
>         Attachments: HIVE-19027.01.patch, HIVE-19027.02.patch, HIVE-19027.03.patch, HIVE-19027.04.patch, HIVE-20006.01.patch, HIVE-20006.02.patch, HIVE-20006.03.patch, HIVE-20006.04.patch, HIVE-20006.05.patch, HIVE-20006.06.patch, HIVE-20006.07.patch, HIVE-20006.patch
>
>
> The main points:
>  - Only MVs that use transactional tables can have a time window value of 0. Those are the only MVs that can be guaranteed to not be outdated when a query is executed.
>  - For MVs that +cannot be outdated+, comparison is based on valid write id lists.
>  - For MVs that +can be outdated+:
>  ** The window for valid outdated MVs can be specified in intervals of 1 minute.
>  ** A materialized view is outdated if it was built before that time window and any source table has been modified since.
> A time window of -1 means to always use the materialized view for rewriting without any checks concerning its validity. If a materialized view uses an external table, the only way to trigger the rewriting would be to set the property to -1, since currently we do not capture for validation purposes whether the external source tables have been modified since the MV was created or not.



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