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From "Stephen Miller (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-9576) ALTER TABLE STORED AS - change storage format and/or compression
Date Wed, 17 Feb 2016 16:36:18 GMT

    [ https://issues.apache.org/jira/browse/HIVE-9576?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15150740#comment-15150740
] 

Stephen Miller commented on HIVE-9576:
--------------------------------------

If it helps, the following command does work:

CREATE TABLE MyNewTable
LIKE MyOldTable
STORED AS (e.g.) PARQUET;

So at least you can copy over the schema easily.

I suspect changing storage type under the hood is trickier than it sounds if you want the
table to remain writeable during the process; there would be delta files involved.

> ALTER TABLE STORED AS - change storage format and/or compression
> ----------------------------------------------------------------
>
>                 Key: HIVE-9576
>                 URL: https://issues.apache.org/jira/browse/HIVE-9576
>             Project: Hive
>          Issue Type: New Feature
>          Components: Compression, File Formats, Parser, Query Planning, Query Processor,
Serializers/Deserializers, SQL, StorageHandler
>    Affects Versions: 0.14.0
>         Environment: HDP 2.2
>            Reporter: Hari Sekhon
>
> Feature request to support rewriting a table into a different format or compression level
via a single alter table statement:
> {code}ALTER TABLE ... STORED AS... TBLPROPERTIES(...){code}
> Currently we create a new table of a different format and do
> {code}INSERT OVERWRITE newtable SELECT * FROM oldtable{code}
> but a colleague has just asked me why this can't be handled by a single alter statement
via a tempory table replacement under the hood, which seems like a fair question.
> Best Regards,
> Hari Sekhon
> http://www.linkedin.com/in/harisekhon



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