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https://issues.apache.org/jira/browse/HBASE-2265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12888102#action_12888102
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ryan rawson commented on HBASE-2265:
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done

On Tue, Jul 13, 2010 at 3:06 PM, Pranav Khaitan



> HFile and Memstore should maintain minimum and maximum timestamps
> -----------------------------------------------------------------
>
>                 Key: HBASE-2265
>                 URL: https://issues.apache.org/jira/browse/HBASE-2265
>             Project: HBase
>          Issue Type: Improvement
>          Components: regionserver
>            Reporter: Todd Lipcon
>            Assignee: Pranav Khaitan
>             Fix For: 0.90.0
>
>         Attachments: TimestampOptimizationV6.patch
>
>
> In order to fix HBASE-1485 and HBASE-29, it would be very helpful to have 
> HFile and Memstore track their maximum and minimum timestamps. This has the 
> following nice properties:
> - for a straight Get, if an entry has been already been found with timestamp 
> X, and X >= HFile.maxTimestamp, the HFile doesn't need to be checked. Thus, 
> the current fast behavior of get can be maintained for those who use strictly 
> increasing timestamps, but "correct" behavior for those who sometimes write 
> out-of-order.
> - for a scan, the "latest timestamp" of the storage can be used to decide 
> which cell wins, even if the timestamp of the cells is equal. In essence, 
> rather than comparing timestamps, instead you are able to compare tuples of 
> (row timestamp, storage.max_timestamp)
> - in general, min_timestamp(storage A) >= max_timestamp(storage B) if storage 
> A was flushed after storage B.

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