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Posted to github@arrow.apache.org by GitBox <gi...@apache.org> on 2021/08/09 15:04:22 UTC

[GitHub] [arrow-datafusion] alamb opened a new pull request #842: Add tests for hash collisions

alamb opened a new pull request #842:
URL: https://github.com/apache/arrow-datafusion/pull/842


   # Which issue does this PR close?
   
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   We generally require a GitHub issue to be filed for all bug fixes and enhancements and this helps us generate change logs for our releases. You can link an issue to this PR using the GitHub syntax. For example `Closes #123` indicates that this PR will close issue #123.
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   Closes https://github.com/apache/arrow-datafusion/issues/841
   
    # Rationale for this change
   1. The hash implementation in `ahash::RandomState` is *very good*, and thus it is very hard to cause hash collisions in tests
   2. Since it is hard to cause hash collisions, it means we do not have test coverage of this case. This is a problem because checking for hash collisions is often required in the performance critical section of code and thus prone to being optimized out
   
   # What changes are included in this PR?
   1. Add a (off by default) feature flag that forces hash collisions
   2. Add a CI test that runs queries using those flags
   3. Updates tests to pass, and filed tickets for those that did not (TODO)
   
   # Are there any user-facing changes?
   No
   


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[GitHub] [arrow-datafusion] Dandandan merged pull request #842: Add tests for hash collisions

Posted by GitBox <gi...@apache.org>.
Dandandan merged pull request #842:
URL: https://github.com/apache/arrow-datafusion/pull/842


   


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