[Documentation] Data types for Dictionary exclude & sort column Data types for Dictionary exclude & sort column
This closes #1907 Project: http://git-wip-us.apache.org/repos/asf/carbondata/repo Commit: http://git-wip-us.apache.org/repos/asf/carbondata/commit/22f78fab Tree: http://git-wip-us.apache.org/repos/asf/carbondata/tree/22f78fab Diff: http://git-wip-us.apache.org/repos/asf/carbondata/diff/22f78fab Branch: refs/heads/branch-1.3 Commit: 22f78faba1b7314297434cf23d898aa5346dea37 Parents: e527c05 Author: sgururajshetty <sgururajshe...@gmail.com> Authored: Thu Feb 1 20:30:12 2018 +0530 Committer: manishgupta88 <tomanishgupt...@gmail.com> Committed: Sat Feb 3 14:17:18 2018 +0530 ---------------------------------------------------------------------- docs/data-management-on-carbondata.md | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/carbondata/blob/22f78fab/docs/data-management-on-carbondata.md ---------------------------------------------------------------------- diff --git a/docs/data-management-on-carbondata.md b/docs/data-management-on-carbondata.md index 0b35ed9..66cc048 100644 --- a/docs/data-management-on-carbondata.md +++ b/docs/data-management-on-carbondata.md @@ -45,13 +45,15 @@ This tutorial is going to introduce all commands and data operations on CarbonDa - **Dictionary Encoding Configuration** - Dictionary encoding is turned off for all columns by default from 1.3 onwards, you can use this command for including columns to do dictionary encoding. + Dictionary encoding is turned off for all columns by default from 1.3 onwards, you can use this command for including or excluding columns to do dictionary encoding. Suggested use cases : do dictionary encoding for low cardinality columns, it might help to improve data compression ratio and performance. ``` TBLPROPERTIES ('DICTIONARY_INCLUDE'='column1, column2') - ``` + ``` + NOTE: DICTIONARY_EXCLUDE supports only int, string, timestamp, long, bigint, and varchar data types. + - **Inverted Index Configuration** By default inverted index is enabled, it might help to improve compression ratio and query speed, especially for low cardinality columns which are in reward position. @@ -64,8 +66,9 @@ This tutorial is going to introduce all commands and data operations on CarbonDa - **Sort Columns Configuration** This property is for users to specify which columns belong to the MDK(Multi-Dimensions-Key) index. - * If users don't specify "SORT_COLUMN" property, by default MDK index be built by using all dimension columns except complex datatype column. - * If this property is specified but with empty argument, then the table will be loaded without sort.. + * If users don't specify "SORT_COLUMN" property, by default MDK index be built by using all dimension columns except complex data type column. + * If this property is specified but with empty argument, then the table will be loaded without sort. + * This supports only string, date, timestamp, short, int, long, and boolean data types. Suggested use cases : Only build MDK index for required columns,it might help to improve the data loading performance. ```