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https://issues.apache.org/jira/browse/HIVE-5317?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13826191#comment-13826191
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Edward Capriolo commented on HIVE-5317:
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{quote}
Ed,
If you don't use the insert, update, and delete commands, they won't impact
your use of Hive. On the other hand, there are a wide number of users who need
ACID and updates.
{quote}
Why don't those users just use an acid database?
{quote}
The dimension tables have primary keys and are typically bucketed and sorted on
those keys.
{quote}
All the use cases defined seem to be exactly what hive is not built for.
1) Hive does not do much/any optimization of a table when it is sorted.
2) Hive tables do not have primary keys
3) Hive is not made to play with tables of only a few rows
It seems like the idea is to turn hive and hive metastore into a once shot
database for processes that can easily be done differently.
{quote}
Once a day a small set (up to 100k rows) of records need to be deleted for
regulatory compliance.
{quote}
1. squoop export to rdbms
2. run query on rdbms
3. write back to hive.
I am not ready to vote -1, but I am struggling to understand why anyone would
want to use hive to solve the use cases described. This seems like a square peg
in a round hole solution. It feels like something that belongs outside of hive.
It feels a lot like this:
http://db.cs.yale.edu/hadoopdb/hadoopdb.html
> Implement insert, update, and delete in Hive with full ACID support
> -------------------------------------------------------------------
>
> Key: HIVE-5317
> URL: https://issues.apache.org/jira/browse/HIVE-5317
> Project: Hive
> Issue Type: New Feature
> Reporter: Owen O'Malley
> Assignee: Owen O'Malley
> Attachments: InsertUpdatesinHive.pdf
>
>
> Many customers want to be able to insert, update and delete rows from Hive
> tables with full ACID support. The use cases are varied, but the form of the
> queries that should be supported are:
> * INSERT INTO tbl SELECT …
> * INSERT INTO tbl VALUES ...
> * UPDATE tbl SET … WHERE …
> * DELETE FROM tbl WHERE …
> * MERGE INTO tbl USING src ON … WHEN MATCHED THEN ... WHEN NOT MATCHED THEN
> ...
> * SET TRANSACTION LEVEL …
> * BEGIN/END TRANSACTION
> Use Cases
> * Once an hour, a set of inserts and updates (up to 500k rows) for various
> dimension tables (eg. customer, inventory, stores) needs to be processed. The
> dimension tables have primary keys and are typically bucketed and sorted on
> those keys.
> * Once a day a small set (up to 100k rows) of records need to be deleted for
> regulatory compliance.
> * Once an hour a log of transactions is exported from a RDBS and the fact
> tables need to be updated (up to 1m rows) to reflect the new data. The
> transactions are a combination of inserts, updates, and deletes. The table is
> partitioned and bucketed.
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