[jira] [Commented] (PIG-4963) Add a Bloom join

["Rohini Palaniswamy (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PIG-4963?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15743064#comment-15743064 ] 

Rohini Palaniswamy commented on PIG-4963:
-----------------------------------------

[~szita],
   I have already been working on this. Would it be ok if I re-assigned it to myself?

> Add a Bloom join
> ----------------
>
>                 Key: PIG-4963
>                 URL: https://issues.apache.org/jira/browse/PIG-4963
>             Project: Pig
>          Issue Type: New Feature
>            Reporter: Rohini Palaniswamy
>            Assignee: Adam Szita
>
> In PIG-4925, added option to pass BloomFilter as a scalar to bloom function. But found that actually using it for big data which required huge vector size was very inefficient and led to OOM.
>    I had initially calculated that it would take around 12MB bytearray for 100 million vectorsize (100000000 + 7) / 8 = 12500000 bytes) and that would be the scalar value broadcasted and would not take much space. But problem is 12MB was written out for every input record with BuildBloom$Initial before the aggregation happens and we arrive at the final BloomFilter vector. And with POPartialAgg it runs into OOM issues. 
> If we added a bloom join implementation, which can be combined with hash or skewed join it would boost performance for a lot of jobs. Bloom filter of the smaller tables can be sent to the bigger tables as scalar and data filtered before hash or skewed join is used.



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