[jira] [Created] (TRAFODION-1164) LP Bug: 1443463 - '\N' and empty string are both treated as null when selecting hive table.

["Alice Chen (JIRA)" <ji...@apache.org>]

Alice Chen created TRAFODION-1164:
-------------------------------------

             Summary: LP Bug: 1443463 - '\N' and empty string are both treated as null when selecting hive table.
                 Key: TRAFODION-1164
                 URL: https://issues.apache.org/jira/browse/TRAFODION-1164
             Project: Apache Trafodion
          Issue Type: Bug
            Reporter: Howard Qin
            Assignee: Apache Trafodion
            Priority: Critical
             Fix For: 2.0-incubating


When loading/selecting from hive table,  we treat both empty string and '\N' as null, this doesn't conform with hive behavior, in which, user can configure what null character is.

The issue can be explain in following steps:
1)
>select * from t1;
A            B
-----------  ------------------------------------------------------------------------------------------------------------------------
          4
          1  ?
          2  fsdf
          3  hhah

2)
unload  with null_string '\N' into '/nulltest' select * from t1; 
-bash-4.1$ swhdfs dfs -cat /nulltest/file0-20150410015053-828
4|
1|\N
2|fsdf
3|hhah

3)
hive> create external table nulltest ( A int, B string ) 
         >                                               row format delimited fields terminated by '|'
         >                                                location '/nulltest'
         >                                                tblproperties ('serialization.null.format' = '\\N');

hive> select * from nulltest;
OK
nulltest.a      nulltest.b
4                                                       <--  empty string
1                       NULL
2                       fsdf
3                       hhah

4)
>>select * from hive.hive.nulltest;
A            B
-----------  ------------------------------------------------------------------------------------------------------------------------
          4  ?                               <--  empty string is considered null. 
          1  ?                                  
          2  fsdf
          3  hhah

>select * from t1;
A            B
-----------  ------------------------------------------------------------------------------------------------------------------------
          4                            <-- should consist with t1 and hive.
          1  ?
          2  fsdf
          3  hhah
Assigned to LaunchPad User khaled Bouaziz



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