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From "Jasper Knulst (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HIVE-8871) Hive Hbase Integration : Support for NULL value columns
Date Fri, 14 Nov 2014 13:42:33 GMT
Jasper Knulst created HIVE-8871:
-----------------------------------

             Summary: 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


If you map Hive to a Hbase table where one CF only has qualifiers but no values, Hive always
outputs ' {} ' for that key. As soon as you put a single byte (like a space) as value you'll
get a return like this ' {"20140911"," "}.



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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