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https://issues.apache.org/jira/browse/HBASE-13109?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14364356#comment-14364356
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Andrew Purtell commented on HBASE-13109:
----------------------------------------
I've confirmed 0.98.12 snapshots are available in Apache Maven now.
Be sure the Apache snapshots repository is included in your POM:
{noformat}
<repository>
<id>apache.snapshots</id>
<url>http://repository.apache.org/snapshots/</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
{noformat}
Use the versions "0.98.12-hadoop2-SNAPSHOT" for the Hadoop 2 build,
"0.98.12-hadoop1-SNAPSHOT" for the Hadoop 1 build.
> Make better SEEK vs SKIP decisions during scanning
> --------------------------------------------------
>
> Key: HBASE-13109
> URL: https://issues.apache.org/jira/browse/HBASE-13109
> Project: HBase
> Issue Type: Improvement
> Reporter: Lars Hofhansl
> Assignee: Lars Hofhansl
> Fix For: 2.0.0, 1.0.1, 1.1.0, 0.98.12
>
> Attachments: 13109-0.98-v4.txt, 13109-trunk-v2.txt,
> 13109-trunk-v3.txt, 13109-trunk-v4.txt, 13109-trunk-v5.txt, 13109-trunk.txt,
> nextIndexKVChange_new.patch
>
>
> I'm re-purposing this issue to add a heuristic as to when to SEEK and when to
> SKIP Cells. This has come up in various issues, and I think I have a way to
> finally fix this now. HBASE-9778, HBASE-12311, and friends are related.
> --- Old description ---
> This is a continuation of HBASE-9778.
> We've seen a scenario of a very slow scan over a region using a timerange
> that happens to fall after the ts of any Cell in the region.
> Turns out we spend a lot of time seeking.
> Tested with a 5 column table, and the scan is 5x faster when the timerange
> falls before all Cells' ts.
> We can use the lookahead hint introduced in HBASE-9778 to do opportunistic
> SKIPing before we actually seek.
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