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https://issues.apache.org/jira/browse/KUDU-2846?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16865670#comment-16865670
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Grant Henke commented on KUDU-2846:
-----------------------------------
Some of this work has been completed in
[349aeaab3|https://github.com/apache/kudu/commit/349aeaab3] and
[fe7c15759|https://github.com/apache/kudu/commit/fe7c15759].
> Special case predicate evaluation for SIMD support
> --------------------------------------------------
>
> Key: KUDU-2846
> URL: https://issues.apache.org/jira/browse/KUDU-2846
> Project: Kudu
> Issue Type: Improvement
> Components: perf, tserver
> Reporter: Todd Lipcon
> Priority: Major
>
> In the common case of predicate evaluation on primitive types, we can likely
> improve performance as follows:
> - doing the comparisons while ignoring nullability and selectedness (any null
> or unselected cells may have junk data, which causes a junk comparison result)
> - take the resulting bitmask of comparison results and use bitwise ops to
> account for null/unselected cells to ensure that those result in a 'false'
> comparison
> For some types of comparisons this can result in SIMD operations. For others,
> at least, this will remove most branches from the path. This should speed up
> queries like TPCH Q6 which spends 25% of its time in predicate evaluation.
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