Xuefu Zhang created HIVE-7060:
---------------------------------

             Summary: Column stats give incorrect min and distinct_count
                 Key: HIVE-7060
                 URL: https://issues.apache.org/jira/browse/HIVE-7060
             Project: Hive
          Issue Type: Bug
          Components: Statistics
    Affects Versions: 0.13.0
            Reporter: Xuefu Zhang


It seems that the result from column statistics isn't correct on two measures 
for numeric columns: min (which is always 0) and distinct count. Here is an 
example:

{code}
select count(distinct avgTimeOnSite), min(avgTimeO from 
UserVisits_web_text_nonenSite) from UserVisits_web_text_none;
...
OK
9       1
Time taken: 9.747 seconds, Fetched: 1 row(s)
(code}

The statisitics for the column:
{code}
PREHOOK: query: desc formatted UserVisits_web_text_none avgTimeOnSite
PREHOOK: type: DESCTABLE
PREHOOK: Input: default@uservisits_web_text_none
POSTHOOK: query: desc formatted UserVisits_web_text_none avgTimeOnSite
POSTHOOK: type: DESCTABLE
POSTHOOK: Input: default@uservisits_web_text_none
# col_name              data_type               min                     max     
                num_nulls               distinct_count          avg_col_len     
        max_col_len             num_trues               num_falses              
comment

avgTimeOnSite           int                     0                       9       
                0                       11                      null            
        null                    null               
{code}



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Reply via email to