[carbondata] branch master updated: [CARBONDATA-4010] Doc changes for long strings.

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indhumuthumurugesh pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/carbondata.git


The following commit(s) were added to refs/heads/master by this push:
     new 9dfbd91  [CARBONDATA-4010] Doc changes for long strings.
9dfbd91 is described below

commit 9dfbd9122e2e1f94dbd351ed6d6f2e039c3818cf
Author: Nihal ojha <ni...@gmail.com>
AuthorDate: Fri Sep 25 14:26:07 2020 +0530

    [CARBONDATA-4010] Doc changes for long strings.
    
    Why is this PR needed?
    Added documentation change for the handling of long strings(length greater than 32000) as bad record and set/unset of longStringColumns.
    
    What changes were proposed in this PR?
    Added documentation change for the handling of long strings(length greater than 32000) as bad record and set/unset of longStringColumns.
    
    Does this PR introduce any user interface change?
    No
    
    Is any new testcase added?
    No
    
    This closes #3959
    
    Co-authored-by: Karan980 <ka...@gmail.com>
---
 docs/ddl-of-carbondata.md | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/docs/ddl-of-carbondata.md b/docs/ddl-of-carbondata.md
index ca9a321..56d7e4e 100644
--- a/docs/ddl-of-carbondata.md
+++ b/docs/ddl-of-carbondata.md
@@ -426,7 +426,8 @@ CarbonData DDL statements are documented here,which includes:
    - ##### String longer than 32000 characters
 
      In common scenarios, the length of string is less than 32000,
-     so carbondata stores the length of content using Short to reduce memory and space consumption.
+     so carbondata stores the length of content using Short to reduce memory and space consumption,
+     and it handles strings which have length greater than 32000 as a bad record. Refer [bad record handling](https://github.com/apache/carbondata/blob/master/docs/dml-of-carbondata.md#bad-records-handling) section for better understanding.
      To support string longer than 32000 characters, carbondata introduces a table property called `LONG_STRING_COLUMNS`.
      For these columns, carbondata internally stores the length of content using Integer.
 
@@ -812,7 +813,19 @@ Users can specify which columns to include and exclude for local dictionary gene
        ```
        ALTER TABLE tablename UNSET TBLPROPERTIES('SORT_SCOPE')
        ```
+     - ##### Long String Columns
+       Example to SET Long String Columns:
+       ```
+       ALTER TABLE tablename SET TBLPROPERTIES('LONG_STRING_COLUMNS'='column1')
+       ```
+       **NOTE:** Only string columns can be set to long string columns. Cannot set sort columns to long string columns.
 
+       Example to UNSET Long String Columns:
+       ```
+       ALTER TABLE tablename UNSET TBLPROPERTIES('LONG_STRING_COLUMNS')
+       ```
+       **NOTE:** On unset, long string columns are set to their original datatypes.
+ 
      - ##### SORT COLUMNS
        Example to SET SORT COLUMNS:
        ```