Hi Jacky, If user want to create a cube on main table, does he/she have to create multiple pre-aggregate tables? It will be a heavy workload to write so many CTAS commands. If user only need create a few pre-agg tables, current carbon already can support this requirement, user can create table first and then use insert into select statement. The only different is user need to query the pre-agg table instead of main table.
So maybe we can enable user to create a cube model( in schema or metafile?) which contains multiple pre-aggregation definition and carbon can create those pre-agg tables automatically according to the model. That would be more easy for using and maintenance. Regards, Lionel On Sun, Oct 15, 2017 at 3:56 PM, Jacky Li <jacky.li...@qq.com> wrote: > 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 <chenliang6...@gmail.com> 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 > > > > > > -- > > Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556. > n5.nabble.com/ > > > >
