Posted by
Jacky Li on
Oct 15, 2017; 7:56am
URL: http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/Discussion-Support-pre-aggregate-table-to-improve-OLAP-performance-tp24040p24073.html
Hi Liang,
For alter table, data update/delete, and delete segment, they are the same.
So I write in document “ User can manually perform this operation and rebuild pre-aggregate table as
update scenario”
User need to drop the associated aggregate table and perform alter table, or data update/delete, or delete segment operation, then he can create the pre-agg table using CTAS command again, and the pre-aggregate table will be rebuilt.
Regards,
Jacky
> 在 2017年10月15日，下午2:50，Liang Chen <
[hidden email]> 写道：
>
> Hi Jacky
>
> Thanks for you started this discussion, this is a great feature in
> carbondata.
>
> One question:
> For sub_jar "Handle alter table scenarios for aggregation table", please
> give more detail info.
> Just i viewed the pdf attachment as below, looks no need to do any handles
> for agg table if users do alter for main table. so can you provide more
> detail, which scenarios need to be handled?
> ------------------------------------------------------------------------------------------
> Adding of new column will not impact agg table.
> Deleting or renaming existing column may invalidate agg tables, if it
> invalidate, the operation
> will be rejected.
> User can manually perform this operation and rebuild pre-aggregate table as
> update
> scenario.
>
> Regards
> Liang
>
>
> --
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