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https://issues.apache.org/jira/browse/HBASE-9751?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13793543#comment-13793543
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Vladimir Rodionov commented on HBASE-9751:
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The performance advantage of *Bytes.equalsTo* over *Bytes.compareTo* outweigh
any possible extra IO look up regardless of a size of a Scan operation. For
short scans it will work as pre-fetching of index and data , for long scans -
the extra IO seek time is negligible.
Sure, ThreadLocals needs to be removed from scanners. Too expensive, especially
when you have direct access to memory or cache.
> 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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