QiangCai created CARBONDATA-3347:
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             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]



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