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From "Prasanth Jayachandran (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-11312) ORC format: where clause with CHAR data type not returning any rows
Date Mon, 03 Aug 2015 05:15:05 GMT

     [ https://issues.apache.org/jira/browse/HIVE-11312?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Prasanth Jayachandran updated HIVE-11312:
-----------------------------------------
    Attachment: HIVE-11312.2.patch

We don't need a CHAR type in sargs. Instead we need to convert the constant literal to column
type. For charColumn = "1", the literal "1" should be padded to the length specified in charColumn
type info. ORC stores char columns  as is without stripping off the trailing white spaces.
The column stats will also have spaces at the end. If we map the constant literal to the column
type then we can get away with not having CHAR type in sargs.

[~gopalv]/[~owen.omalley] Can someone take a look at the patch?

> ORC format: where clause with CHAR data type not returning any rows
> -------------------------------------------------------------------
>
>                 Key: HIVE-11312
>                 URL: https://issues.apache.org/jira/browse/HIVE-11312
>             Project: Hive
>          Issue Type: Bug
>          Components: Query Processor
>    Affects Versions: 1.2.0, 1.2.1
>            Reporter: Thomas Friedrich
>            Assignee: Thomas Friedrich
>              Labels: orc
>         Attachments: HIVE-11312.1.patch, HIVE-11312.2.patch
>
>
> Test case:
> Setup: 
> create table orc_test( col1 string, col2 char(10)) stored as orc tblproperties ("orc.compress"="NONE");
> insert into orc_test values ('val1', '1');
> Query:
> select * from orc_test where col2='1'; 
> Query returns no row.
> Problem is introduced with HIVE-10286, class RecordReaderImpl.java, method evaluatePredicateRange.
> Old code:
> - Object baseObj = predicate.getLiteral(PredicateLeaf.FileFormat.ORC);
> - Object minValue = getConvertedStatsObj(min, baseObj);
> - Object maxValue = getConvertedStatsObj(max, baseObj);
> - Object predObj = getBaseObjectForComparison(baseObj, minValue);
> New code:
> + Object baseObj = predicate.getLiteral();
> + Object minValue = getBaseObjectForComparison(predicate.getType(), min);
> + Object maxValue = getBaseObjectForComparison(predicate.getType(), max);
> + Object predObj = getBaseObjectForComparison(predicate.getType(), baseObj);
> The values for min and max are of type String which contain as many characters as the
CHAR column indicated. For example if the type is CHAR(10), and the row has value 1, the value
of String min is "1         ";
> Before Hive 1.2, the method getConvertedStatsObj would call StringUtils.stripEnd(statsObj.toString(),
null); which would remove the trailing spaces from min and max. Later in the compareToRange
method, it was able to compare "1" with "1".
> In Hive 1.2 with the use getBaseObjectForComparison method, it simply returns obj.String
if the data type is String, which means minValue and maxValue are still "1         ".
> As a result, the compareToRange method will return a wrong value ("1".compareTo("1  
      ")  -9 instead of 0.



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