[jira] [Assigned] (HIVE-20434) analyze on an empty partition doesn't produce correct stats

["Sergey Shelukhin (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-20434?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Sergey Shelukhin reassigned HIVE-20434:
---------------------------------------


> analyze on an empty partition doesn't produce correct stats
> -----------------------------------------------------------
>
>                 Key: HIVE-20434
>                 URL: https://issues.apache.org/jira/browse/HIVE-20434
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Sergey Shelukhin
>            Assignee: Ashutosh Chauhan
>            Priority: Major
>
> {noformat}
> set hive.stats.dbclass=fs;
> set hive.stats.fetch.column.stats=true;
> set datanucleus.cache.collections=false;
> set hive.merge.mapfiles=false;
> set hive.merge.mapredfiles=false;
> set hive.mapred.mode=nonstrict;
> set hive.stats.autogather=true;
> set hive.stats.column.autogather=true;
> set hive.compute.query.using.stats=true;
> set hive.explain.user=false;
> set hive.fetch.task.conversion=none;
> set hive.query.results.cache.enabled=false;
> create table stats_part(key int,value string) partitioned by (p int) tblproperties ("transactional"="false");
> insert into table stats_part partition(p=101) values (1, "foo");
> explain select count(key) from stats_part; -- <== stats are correct
> ALTER TABLE stats_part CHANGE COLUMN key key2 int;
> explain select count(key2) from stats_part; -- <== stats are now incorrect
> analyze table stats_part partition(p) compute statistics for columns;
> explain select count(key2) from stats_part; -- <== stats are now correct again
> alter table stats_part add partition(p=105);
> explain select count(key2) from stats_part; -- <== stats are now incorrect
> analyze table stats_part partition(p) compute statistics for columns;
> explain select count(key2) from stats_part; -- <== stats are still incorrect!
> drop table stats_part;
> {noformat}
> Seems like it's impossible to have correct stats on a table with an empty partition.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)