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https://issues.apache.org/jira/browse/KYLIN-1695?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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kangkaisen updated KYLIN-1695:
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Attachment: KYLIN-1695.patch
this patch adds one configuration "kylin.hive.calculate.cardinality.enabled" ,
the default is "false"
> disable cardinality calculation job when loading hive table
> -----------------------------------------------------------
>
> Key: KYLIN-1695
> URL: https://issues.apache.org/jira/browse/KYLIN-1695
> Project: Kylin
> Issue Type: Bug
> Components: Job Engine
> Affects Versions: v1.5.1
> Reporter: kangkaisen
> Assignee: Dong Li
> Attachments: KYLIN-1695.patch
>
>
> When user loads/reloads hive tables from web console, kylin will submit a mr
> job asynchronously to calculate column cardinalities. This has four major
> problems:
> # the calculated cardinality is stored in table metadata, but never used in
> cubing/querying
> # table may change after loading, so the cardinality doesn't necessarily
> reflect the actual value
> # the current `HiveColumnCardinalityJob` has many limitations, e.g., it
> doesn't support views
> # the `HiveColumnCardinalityJob` may use lots of resources when computing
> cardinality of partitioned table
> Due to these problems, we should disable it by default and (maybe) remove it
> in future releases.
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