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https://issues.apache.org/jira/browse/HBASE-9751?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13793522#comment-13793522
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Vladimir Rodionov commented on HBASE-9751:
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OK.There are two stopRows: stopRow original from Scan and calculated
*stopRowReal* which is the closest *real* row in a Store such that stopRowReal
<= stopRow and Scanner.nextAfter(stopRowReal) > stopRow.
At the time of a scanner creation (RegionScanner) we find *stopRowReal* and now
we can replace all *compareTo (stopRow)* with *equalsTo(stopRowReal)*?
> 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-trunk.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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