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https://issues.apache.org/jira/browse/HBASE-9751?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lars Hofhansl updated HBASE-9751:
---------------------------------

      Resolution: Fixed
    Hadoop Flags: Reviewed
          Status: Resolved  (was: Patch Available)

Committed to all branches. Thanks for the review Ted.

Note that this is complementary to the scanner related stuff in HBASE-9753 and 
HBASE-9754. Here we use an HFile's metadata to avoid the MVCC altogether.


> Excessive  readpoints checks in StoreFileScanner
> ------------------------------------------------
>
>                 Key: HBASE-9751
>                 URL: https://issues.apache.org/jira/browse/HBASE-9751
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 0.98.0, 0.94.12, 0.96.0
>            Reporter: Vladimir Rodionov
>            Assignee: Lars Hofhansl
>             Fix For: 0.98.0, 0.94.13, 0.96.1
>
>         Attachments: 9751-0.94.txt, 9751-0.94-v2.txt, 9751-trunk.txt, 
> 9751-trunk-v2.txt
>
>
> It seems that usage of skipKVsNewerThanReadpoint in StoreFileScanner can be 
> greatly reduced or even eliminated all together (HFiles are immutable and no 
> new KVs can be inserted after scanner instance is created). The same is true 
> for MemStoreScanner which checks readpoint on every next() and seek(). Each 
> readpoint check is ThreadLocal.get() and it is quite expensive.  



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