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https://issues.apache.org/jira/browse/HIVE-15788?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15980780#comment-15980780
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Prasanth Jayachandran commented on HIVE-15788:
----------------------------------------------

Last time when I did JMH benchmark RoaringBitmap wasn't fast enough and that's 
the reason why I did not use that in first place. I still doubt that this will 
be faster. I am sure this will have better compression but it will have huge 
performance hit. I guess [~jdere] also benchmarked it recently and concluded 
the same (correct me if I am wrong). So I am -1 on replacing the default long[] 
until proven otherwise.

> Implement FastBloomFilter to use RoaringBitmap instead of long[] 
> -----------------------------------------------------------------
>
>                 Key: HIVE-15788
>                 URL: https://issues.apache.org/jira/browse/HIVE-15788
>             Project: Hive
>          Issue Type: Improvement
>          Components: UDF
>            Reporter: Gopal V
>            Assignee: Murali Vemulapati
>         Attachments: HIVE-15788.patch
>
>
> Currently, a bloom filter which is all 1s occupies the exact amount of space 
> as a bloom filter which is sparse.
> This is an entire waste of space and produces memory pressure and generate a 
> massive number of cache misses.



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