[jira] [Created] (HIVE-8524) When table is renamed stats are lost as changes are not propagated to metastore tables TAB_COL_STATS and PART_COL_STATS

["Mostafa Mokhtar (JIRA)" <ji...@apache.org>]

Mostafa Mokhtar created HIVE-8524:
-------------------------------------

             Summary: When table is renamed stats are lost as changes are not propagated to metastore tables TAB_COL_STATS and PART_COL_STATS 
                 Key: HIVE-8524
                 URL: https://issues.apache.org/jira/browse/HIVE-8524
             Project: Hive
          Issue Type: Bug
          Components: Metastore
    Affects Versions: 0.14.0
            Reporter: Mostafa Mokhtar
            Assignee: Gunther Hagleitner
             Fix For: 0.14.0


When a Hive table is renamed that the name is not updated in TAB_COL_STATS and PART_COL_STATS.

Repro 
1) Create table 
2) insert rows
3) Analyze table t1 compute statistics for columns;
4) set hive.stats.fetch.column.stats=true;
5) Explain select * from t1 where c1 > x 
6) ALTER TABLE t1 RENAME TO 2;
7) Explain select * from t2 where c1 > x ; /* stats will be missing */
8) Query the Metastore tables to validate 

According to the documentation Metastore should be updated
{code}
This statement lets you change the name of a table to a different name.
As of version 0.6, a rename on a managed table moves its HDFS location as well. (Older Hive versions just renamed the table in the metastore without moving the HDFS location.)
{code}

Another related issue is that the schema of  the stats table is not consistent with TBLS and DBS as these two table are normalized while TAB_COL_STATS and PART_COL_STATS have TABLE_NAME and DB_NAME denormalized in them.



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