[jira] [Created] (CARBONDATA-3347) support SORT_COLUMNS modification

["QiangCai (JIRA)" <ji...@apache.org>]

QiangCai created CARBONDATA-3347:
------------------------------------

             Summary: 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: QiangCai
         Attachments: sort_columns modification.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.pdf]



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)