Re: [DISCUSSION]implement delta encoding for numeric type column in SORT_COLUMNS

Posted by Jacky Li on
URL: http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/DISCUSSION-implement-delta-encoding-for-numeric-type-column-in-SORT-COLUMNS-tp10124p10216.html


> 在 2017年4月5日，下午6:31，QiangCai <[hidden email]> 写道：
>
> Hi all,
>
>    Now we plan to implement delta encoding for the numeric type column in
> SORT_COLUMNS.
>
>    1. use delta encoding to encode the numeric type data
>

I think the adaptive data type conversion still apply here, right?

>    2. write present metadata to the page header, to record the null value.
>
>    3. improve the compression on no-dictionary string column.
>        use RLE to compress the array of the lengths in LV encoding.
>

I think local dictionary is more suitable for this case

>    Any thoughts, comments and questions ?
>
> Best Regards
> David QiangCai
>
>
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