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https://issues.apache.org/jira/browse/PHOENIX-1278?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14144346#comment-14144346
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Anoop Sam John commented on PHOENIX-1278:
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Can I take this [~ram_krish]?

> Performance degradation for salted tables with guideposts
> ---------------------------------------------------------
>
>                 Key: PHOENIX-1278
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-1278
>             Project: Phoenix
>          Issue Type: Bug
>            Reporter: James Taylor
>
> When a table is salted, we're seeing a degradation in performance using our 
> new guidepost-based parallelization. With salted tables, we do a merge sort 
> with the results from all the parallel scans. I suspect the cause here is 
> that we're doing a merge sort now between more chunks than before (since we 
> chunk everything up more now than we used to). We should group the scans 
> we're doing for the same bucket together and do a concat with those results 
> and then do a merge sort only with the concatenated batches.
> Pls revert PHOENIX-1279 when we implement this.



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