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Re: why sort_columns?

Posted by ravipesala on May 15, 2017; 9:09am
URL: http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/why-sort-columns-tp12663p12687.html

Hi,

You can still use like create table(c1,c2,c7,c4..c6,c3) with out specifying
sort_columns. If you specify like this then it goes to default behavior.
All string, date. timestamp goes to sort_columns in the order you mentioned
in the create table.

Regards,
Ravindra.

On 15 May 2017 at 08:01, [hidden email] <[hidden email]>
wrote:

> hi community,
>
> since we already have many rmdb sqls scripts,we don't want to change them
> too much when migrating to carbon.
> suppose we already have sql script like:
>    "create table (c1,c2,...c7")",
> If we want to change column order to shift most often used column ahead
> when query data,i think it's better change it this way like:
>   "create table(c1,c2,c7,c4..c6,c3)
> rather
>   "create table(c1...c7) tblproperties('sort_columns' = 'c7,c3')"
> because the former way just reordering columns without adding extra
> settings,which is more readable to thos who is familiar with rmdb but not
> with carbon.
>
>
>
> [hidden email]
>



--
Thanks & Regards,
Ravi