[
https://issues.apache.org/jira/browse/HIVE-5317?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13772077#comment-13772077
]
stack commented on HIVE-5317:
-----------------------------
bq. The HBase scan rate is much lower than HDFS, especially with short-circuit
reads.
What kinda of numbers are you talking Owen? Would be interested in knowing
what they are. Implication would be also that it cannot be improved? Or
scanning the files written by hbase offline from a snapshot wouldn't work from
you (snapshots are cheap in hbase. Going by your use cases, you'd be doing
these runs infrequently enough).
bq. HBase is tuned for a write-heavy workloads.
Funny. Often we're accused of the other extreme.
bq. HBase doesn't have a columnar format and can't support column projection.
It doesn't. Too much work to add a storage engine that wrote columnar?
bq. HBase doesn't have the equivalent of partitions or buckets.
In hbase we call them 'Regions'.
> 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.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
