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https://issues.apache.org/jira/browse/HBASE-9969?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13822760#comment-13822760
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Ted Yu commented on HBASE-9969:
-------------------------------
{code}
* @return true if there are more keys, false if all scanners are done
*/
public boolean next(List<Cell> result, int limit) throws IOException {
...
+ return loserTree.isEmpty();
}
{code}
Should the return value from loserTree.isEmpty() be negated ?
{code}
+ if (isLazy && loserTree.getNumOfOpenStreams() > 1) {
// If there is only one scanner left, we don't do lazy seek.
{code}
Please update comment above to match the condition.
> Improve KeyValueHeap using loser tree
> -------------------------------------
>
> Key: HBASE-9969
> URL: https://issues.apache.org/jira/browse/HBASE-9969
> Project: HBase
> Issue Type: Improvement
> Reporter: Chao Shi
> Attachments: hbase-9969.patch, hbase-9969.patch,
> kvheap-benchmark.png, kvheap-benchmark.txt
>
>
> LoserTree is the better data structure than binary heap. It saves half of the
> comparisons on each next(), though the time complexity is on O(logN).
> Currently A scan or get will go through two KeyValueHeaps, one is merging KVs
> read from multiple HFiles in a single store, the other is merging results
> from multiple stores. This patch should improve the both cases whenever CPU
> is the bottleneck (e.g. scan with filter over cached blocks, HBASE-9811).
> All of the optimization work is done in KeyValueHeap and does not change its
> public interfaces. The new code looks more cleaner and simpler to understand.
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