[
https://issues.apache.org/jira/browse/CALCITE-4712?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17391856#comment-17391856
]
Julian Hyde commented on CALCITE-4712:
--------------------------------------
I see. I think you are going further than merely 'not collocating' the null
values - you seem to be applying a random function rather than a hash function,
or alternatively, you are
[salting|https://medium.com/appsflyer/salting-your-spark-to-scale-e6f1c87dd18]
the null value before you hash it. Names such as "saltNulls" or
"randomizeNulls" or "roundRobinNulls" might be more descriptive.
> Add RelHashDistribution
> -----------------------
>
> Key: CALCITE-4712
> URL: https://issues.apache.org/jira/browse/CALCITE-4712
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Haisheng Yuan
> Priority: Major
>
> Add RelHashDistribution. The hash distribution should have the following
> properties:
> {code:java}
> 1. ImmutableIntList keys; // distribution keys
> 2. ImmutableList<ImmutableBitSet> equivKeys; // equivalent keys for each
> distribution key
> 3. int bucketNum; // number of buckets or shards
> 4. boolean nullsColocated; // are NULLS colocated?
> 5. String hashFunc; // name or identity of hash function
> {code}
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
