Peter Vary updated HIVE-6980:
    Attachment: HIVE-6980.5.patch

> Drop table by using direct sql
> ------------------------------
>                 Key: HIVE-6980
>                 URL: https://issues.apache.org/jira/browse/HIVE-6980
>             Project: Hive
>          Issue Type: Improvement
>          Components: Metastore
>    Affects Versions: 0.12.0
>            Reporter: Selina Zhang
>            Assignee: Peter Vary
>            Priority: Major
>         Attachments: HIVE-6980.2.patch, HIVE-6980.3.patch, HIVE-6980.4.patch, 
> HIVE-6980.5.patch, HIVE-6980.patch, drop_table_after.png, 
> drop_table_before.png
> Dropping table which has lots of partitions is slow. Even after applying the 
> patch of HIVE-6265, the drop table still takes hours (100K+ partitions). 
> The fixes come with two parts:
> 1. use directSQL to query the partitions protect mode;
> the current implementation needs to transfer the Partition object to client 
> and check the protect mode for each partition. I'd like to move this part of 
> logic to metastore. The check will be done by direct sql (if direct sql is 
> disabled, execute the same logic in the ObjectStore);
> 2. use directSQL to drop partitions for table;
> there maybe two solutions here:
> 1. add "DELETE CASCADE" in the schema. In this way we only need to delete 
> entries from partitions table use direct sql. May need to change 
> datanucleus.deletionPolicy = DataNucleus. 
> 2. clean up the dependent tables by issue DELETE statement. This also needs 
> to turn on datanucleus.query.sql.allowAll
> Both of above solutions should be able to fix the problem. The DELETE CASCADE 
> has to change schemas and prepare upgrade scripts. The second solutions added 
> maintenance cost if new tables added in the future releases.
> Please advice. 

This message was sent by Atlassian JIRA

Reply via email to