Adar Dembo has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/15034 )

Change subject: KUDU-2483 Integrate BlockBloomFilter with ColumnPredicate on 
server side
......................................................................


Patch Set 13:

> In general, the bloom filter is used as run-time filter, especially in a 
> hash-join case. For a computer engine, such as impala, it will wait 1 
> second(default) to produce the bloom filter and then push it down. So, I have 
> another suggestion: maybe we can push it down in the middle of the scan while 
> the filter is not arrived within the specified interval. It should be in the 
> next patch^_^
>
> computer engine -> kudu client -> kudu server
>        [1]            [2]            [3]
>    throw away
>        [0]

That's interesting: are you suggesting we need the ability to add a bloom 
filter predicate to an ongoing scan, rather than just when starting a new scan? 
There's a lot of existing machinery that treats predicates as just another 
aspect of scan configuration (along with e.g. projections), to be applied to a 
new scanner but immutable after that. I think it'd be a fair amount of work to 
change that.

As an alternative, would it be possible to delay the onset of a Kudu scan from 
Impala until the bloom filter can be constructed? Or will doing that stall the 
entire query pipeline?


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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I7ecfd67e9c5fbe459c5b4aed91e0be2a194d433a
Gerrit-Change-Number: 15034
Gerrit-PatchSet: 13
Gerrit-Owner: Bankim Bhavsar <[email protected]>
Gerrit-Reviewer: Adar Dembo <[email protected]>
Gerrit-Reviewer: Bankim Bhavsar <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Yao Xu <[email protected]>
Gerrit-Reviewer: ZhangYao <[email protected]>
Gerrit-Reviewer: helifu <[email protected]>
Gerrit-Comment-Date: Sat, 08 Feb 2020 05:53:43 +0000
Gerrit-HasComments: No

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