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Posted to issues@hive.apache.org by "Eugene Koifman (JIRA)" <ji...@apache.org> on 2017/10/17 00:53:00 UTC

[jira] [Issue Comment Deleted] (HIVE-16669) Fine tune Compaction to take advantage of Acid 2.0

     [ https://issues.apache.org/jira/browse/HIVE-16669?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Eugene Koifman updated HIVE-16669:
----------------------------------
    Comment: was deleted

(was: OK, this is more than just fine tuning.  Suppose we have 
base_8
delta_9
delete_delta_10 - this affects rows in base_8

Minor compaction (as currently implemented (inherited from Acid 1)) will produce delta_9_10 which means all deletes by txn 10 affecting rows in base_8 are lost.

so HIVE-17089 is effectively incomplete w/o this)

> Fine tune Compaction to take advantage of Acid 2.0
> --------------------------------------------------
>
>                 Key: HIVE-16669
>                 URL: https://issues.apache.org/jira/browse/HIVE-16669
>             Project: Hive
>          Issue Type: Bug
>          Components: Transactions
>            Reporter: Eugene Koifman
>            Assignee: Eugene Koifman
>            Priority: Critical
>
> * There is little point using 2.0 vectorized reader since there is no operator pipeline in compaction
> * If minor compaction just concats delete_delta files together, then the 2 stage compaction should always ensure that we have a limited number of Orc readers to do the merging and current OrcRawRecordMerger should be fine
> * ...



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