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Posted to dev@hive.apache.org by "Xuefu Zhang (JIRA)" <ji...@apache.org> on 2014/05/14 19:17:16 UTC
[jira] [Updated] (HIVE-7060) Column stats give incorrect min and
distinct_count
[ https://issues.apache.org/jira/browse/HIVE-7060?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Xuefu Zhang updated HIVE-7060:
------------------------------
Description:
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}
was:
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}
> 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}
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