[jira] [Commented] (CASSANDRA-4710) High key hashing overhead for index scans when using RandomPartitioner

["Jonathan Ellis (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-4710?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13461864#comment-13461864 ] 

Jonathan Ellis commented on CASSANDRA-4710:
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Why is DatabaseDescriptor.getIndexInterval introduced?
                
> High key hashing overhead for index scans when using RandomPartitioner
> ----------------------------------------------------------------------
>
>                 Key: CASSANDRA-4710
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4710
>             Project: Cassandra
>          Issue Type: Bug
>            Reporter: Daniel Norberg
>         Attachments: 0001-SSTableReader-compare-raw-key-when-scanning-index.patch
>
>
> For a workload where the dataset is completely in ram, the md5 hashing of the keys during index scans becomes a bottleneck for reads when using RandomPartitioner, according to profiling.
> Instead performing a raw key equals check in SSTableReader.getPosition() for EQ operations improves throughput by some 30% for my workload (moving the bottleneck elsewhere).

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