[jira] [Updated] (HIVE-18589) java.io.IOException: Not enough history available

["Eugene Koifman (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-18589?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Eugene Koifman updated HIVE-18589:
----------------------------------
       Resolution: Fixed
    Fix Version/s: 3.0.0
           Status: Resolved  (was: Patch Available)

committed to master

thanks Gopal for the review

> java.io.IOException: Not enough history available
> -------------------------------------------------
>
>                 Key: HIVE-18589
>                 URL: https://issues.apache.org/jira/browse/HIVE-18589
>             Project: Hive
>          Issue Type: Bug
>          Components: Transactions
>    Affects Versions: 3.0.0
>            Reporter: Eugene Koifman
>            Assignee: Eugene Koifman
>            Priority: Critical
>             Fix For: 3.0.0
>
>         Attachments: HIVE-18589.01.patch, HIVE-18589.02.patch
>
>
> txnid:17 starts reading T2/P1
> txnid:20 does insert overwrite T1/P1, creates base_20, commits.  txnid:17 still running
> txnid:21 stars reading T1/P1.  It's ValidTxnList will txnid:17 as open.
> before Insert overwrite was supported, only the compactor could produce base_20 by running major compaction.  Major compaction erases history and so a reader with txnid:17 open, can't use base_20.
> Normally, the Cleaner is smart enough to not clean pre-compaction files if it's possible that there is a reader that requires them.  There is a safety check that creates "Not enough history.." error if it finds that the current reader can't properly execute based on the files available.
>  
> with the introduction of IOW on acid tables, there is another way to produce a base.  The difference is that here, the base has no history by definition and so the same check is not needed but is triggered in the scenario above.
>  
>  



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