N Campbell created HIVE-9745:
--------------------------------

             Summary: predicate evaluation of character fields with spaces and 
literals with spaces returns unexpected result
                 Key: HIVE-9745
                 URL: https://issues.apache.org/jira/browse/HIVE-9745
             Project: Hive
          Issue Type: Bug
          Components: SQL
    Affects Versions: 0.14.0
            Reporter: N Campbell


The following query should return 5 rows but Hive returns 3


select rnum, tchar.cchar from tchar where not (  tchar.cchar = ' ' or ( 
tchar.cchar is null and ' ' is null ))

Consider the following project of the base table


select rnum, tchar.cchar, 
case tchar.cchar when ' ' then 'space' else 'not space' end, 
case when tchar.cchar is null then 'is null' else 'not null' end, case when ' ' 
is null then 'is null' else 'not null' end
from tchar
order by rnum

Row 0 is a NULL
Row 1 was loaded with a zero length string ''
Row 2 was loaded with a single space ' '

rnum    tchar.cchar     _c2     _c3     _c4
0       <null>  not space       is null not null
1                                               not space       not null        
not null
2                                               not space       not null        
not null
3       BB                                      not space       not null        
not null
4       EE                                      not space       not null        
not null
5       FF                                      not space       not null        
not null

Explicitly type cast the literal which many  SQL developers would not expect 
need to do.

select rnum, tchar.cchar, 
case tchar.cchar when cast(' ' as char(1)) then 'space' else 'not space' end, 
case when tchar.cchar is null then 'is null' else 'not null' end, case when 
cast( ' ' as char(1)) is null then 'is null' else 'not null' end
from tchar
order by rnum

rnum    tchar.cchar     _c2     _c3     _c4
0       <null>  not space       is null not null
1                                               space   not null        not null
2                                               space   not null        not null
3       BB                                      not space       not null        
not null
4       EE                                      not space       not null        
not null
5       FF                                      not space       not null        
not null


create table  if not exists T_TCHAR ( RNUM int , CCHAR char(32 )    )
ROW FORMAT DELIMITED FIELDS TERMINATED BY '|' LINES TERMINATED BY '\n' 
 STORED AS TEXTFILE  ;

0|\N
1|
2| 
3|BB
4|EE
5|FF


create table  if not exists TCHAR ( RNUM int , CCHAR char(32 )    )
 STORED AS orc  ;

insert overwrite table TCHAR select * from  T_TCHAR;




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