[
https://issues.apache.org/jira/browse/HIVE-18589?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16348899#comment-16348899
]
Eugene Koifman commented on HIVE-18589:
---------------------------------------
no related failures
[~gopalv] could you review please
> 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
> 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.
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
