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From "Christopher (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-8871) Hive Hbase Integration : Support for NULL value columns
Date Fri, 03 Mar 2017 20:50:46 GMT

    [ https://issues.apache.org/jira/browse/HIVE-8871?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15895005#comment-15895005
] 

Christopher commented on HIVE-8871:
-----------------------------------

A concern that I have is that currently in order to perform an update in a hive table, one
uses NULLs as place holders.  Those NULLs are ignored if it is a preexisting record.

CREATE TABLE hbase_table_emp(id int, name string, role string)
STORED BY 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
WITH SERDEPROPERTIES ("hbase.columns.mapping" = ":key,cf1:name,cf1:role")
TBLPROPERTIES ("hbase.table.name" = "emp");
insert into hbase_table_emp select 1,'bob', 'admin';
insert into hbase_table_emp select 2,'bobby', 'user';
select * from  hbase_table_emp;
insert into hbase_table_emp select 1,null, 'superadmin';

See "bob" remains as "bob"...


> Hive Hbase Integration : Support for NULL value  columns
> --------------------------------------------------------
>
>                 Key: HIVE-8871
>                 URL: https://issues.apache.org/jira/browse/HIVE-8871
>             Project: Hive
>          Issue Type: Bug
>          Components: HBase Handler
>    Affects Versions: 0.10.0
>            Reporter: Jasper Knulst
>              Labels: features
>
> If you map a Hive column to a Hbase CF where the CF only has qualifiers but no values,
Hive always outputs ' {} ' for that key. This hides the fact that qualifiers do exist within
the CF. As soon as you put a single byte (like a space) as value you'll get a return like
this ' {"20140911"," "} in Hive.
> Since it is a common data modelling technique in Hbase to not use the value (and essentially
use the qualifier in a CF as value holder) I think it would be worthwhile to have some support
for this in the Hbase handler. 
> A solution could be to show a data structure like  CF:qualifier:<NULL> like this:
{"20140911",""}
> , where '20140911' is the qualifier and NULL value in Hbase are shown as empty json strings.
> CREATE EXTERNAL TABLE hb_test (
>   userhash string,
>   count bigint,
>   dates map<string,string>)
> STORED BY 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
> WITH SERDEPROPERTIES (
>   "hbase.columns.mapping" =
>   ":key,SUM:COUNT,DATES:",
> "hbase.table.default.storage.type" = "binary"
> )
> TBLPROPERTIES("hbase.table.name" = "test");



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