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https://issues.apache.org/jira/browse/CARBONDATA-3347?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
David Cai resolved CARBONDATA-3347.
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Resolution: Fixed
> support SORT_COLUMNS modification
> ---------------------------------
>
> Key: CARBONDATA-3347
> URL:
https://issues.apache.org/jira/browse/CARBONDATA-3347> Project: CarbonData
> Issue Type: New Feature
> Components: spark-integration
> Reporter: David Cai
> Assignee: David Cai
> Priority: Major
> Attachments: sort_columns modification.pdf, sort_columns modification_v2.pdf
>
>
> *Background*
> Now SORT_COLUMNS can’t be modified after the table is created. If we want to modify SORT_COLUMNS on this table, we need to create a new table and migrate data. If the data is huge, the migration will take a long time and even impact the user business.
> SORT_SCOPE in table properties can be modified now. And we can specify new SORT_SCOPE during data loading. Carbon index file will mark whether this segment is sorted or not. So the different segments maybe have different SORT_SCOPE.
> *Mo**tivation*
> After the table is created, the user can adjust SORT_SCOPE/SORT_COLUMNS according to their business. History segments will still use old SORT_SCOPE/SORT_COLUMNS, but the user also can resort old segments one by one if need.
> But we still suggest the user give a proper SORT_SCOPE/SORT_COLUMNS when they create the table because the modification will take many resources to resort data of old segments.
>
> please check design doc for more detail.
> [^sort_columns modification_v2.pdf]
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