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https://issues.apache.org/jira/browse/HBASE-12311?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lars Hofhansl updated HBASE-12311:
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    Attachment: 12311-v3.txt

Everything hooked up. Not pretty really. Better be a good perf improvement, 
will test when I get to this next.

> Version stats in HFiles?
> ------------------------
>
>                 Key: HBASE-12311
>                 URL: https://issues.apache.org/jira/browse/HBASE-12311
>             Project: HBase
>          Issue Type: Brainstorming
>            Reporter: Lars Hofhansl
>         Attachments: 12311-v2.txt, 12311-v3.txt, 12311.txt, 
> CellStatTracker.java
>
>
> In HBASE-9778 I basically punted the decision on whether doing repeated 
> scanner.next() called instead of the issueing (re)seeks to the user.
> I think we can do better.
> One way do that is maintain simple stats of what the maximum number of 
> versions we've seen for any row/col combination and store these in the 
> HFile's metadata (just like the timerange, oldest Put, etc).
> Then we estimate fairly accurately whether we have to expect lots of versions 
> (i.e. seek between columns is better) or not (in which case we'd issue 
> repeated next()'s).



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