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https://issues.apache.org/jira/browse/KYLIN-5837?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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pengfei.zhan resolved KYLIN-5837.
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Resolution: Fixed
> After turning off the computed column function, the query cannot hit the
> existing recommended index
> ---------------------------------------------------------------------------------------------------
>
> Key: KYLIN-5837
> URL: https://issues.apache.org/jira/browse/KYLIN-5837
> Project: Kylin
> Issue Type: Bug
> Components: Query Engine
> Affects Versions: 5.0-beta
> Reporter: Zhimin Wu
> Assignee: Zhimin Wu
> Priority: Major
> Fix For: 5.0.0
>
>
> *Dev Design*
> * The configuration parameter
> "kylin.metadata.only-reuse-user-defined-computed-column=false" is designed to
> enable the usage of user-defined computed columns for reusing only. This
> decouples the feature of shielding columns from the configuration, which
> means that the shielding column feature can still be used even with this
> parameter set to false.
> * By default, Kylin uses computed columns (CC) for implicit column
> conversions, which means that user-defined computed columns can replace
> implicit expressions. However, if the configuration parameter
> "kylin.query.implicit-computed-column-convert" is set to "false", the
> user-defined computed columns will not be used for implicit column
> conversions.
> * The configuration parameter "kylin.query.agg-computed-column-rewrite" is
> related to computed columns v2 and it replaces columns at the semantic
> RelNode level, while "kylin.query.implicit-computed-column-convert" performs
> column replacements at the SqlNode level. As a general rule, if
> "kylin.query.implicit-computed-column-convert" is set to false, then
> "kylin.query.agg-computed-column-rewrite" will not take effect either.
> However, if "kylin.query.implicit-computed-column-convert" is set to true,
> then "kylin.query.agg-computed-column-rewrite" can be set to either true or
> false.
> * All three configurations can now be modified at the project level.
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