[jira] [Commented] (DRILL-7117) Support creation of histograms for numeric data types (except Decimal) and date/time/timestamp

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-7117?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16799858#comment-16799858 ] 

ASF GitHub Bot commented on DRILL-7117:
---------------------------------------

amansinha100 commented on pull request #1715: DRILL-7117: Support creation of equi-depth histogram for selected dat…
URL: https://github.com/apache/drill/pull/1715
 
 
   …a types.
   
   - This PR adds support for creating equi-depth histograms on the following data types: INT, BIGINT, FLOAT4, FLOAT8, DATE, TIME, TIMESTAMP and BOOLEAN.   No selectivity calculations have been modified yet (that will be done in a later PR).  
   
   - The histogram is built using the t-digest approximation algorithm and associated data structure.  
   Please see details in [DRILL-7117](https://issues.apache.org/jira/browse/DRILL-7117) and the parent JIRA [DRILL-6992](https://issues.apache.org/jira/browse/DRILL-6992) which contains a link to the design document. 
   
   - The same ANALYZE command used for NDV etc will also gather histograms and no new syntax has been added.  For testing, I have done a bunch of manual testing using both skewed and uniform distributions and with different data types.  Please see [DRILL-7117](https://issues.apache.org/jira/browse/DRILL-7117) for results of such testing.  No unit tests have been added yet since the bucket boundaries change slightly by the underlying t-digest.  Making this repeatable and unit-testable needs some thinking and I will do this in a follow-up PR. 
   
   
 
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> Support creation of histograms for numeric data types (except Decimal) and date/time/timestamp
> ----------------------------------------------------------------------------------------------
>
>                 Key: DRILL-7117
>                 URL: https://issues.apache.org/jira/browse/DRILL-7117
>             Project: Apache Drill
>          Issue Type: Sub-task
>          Components: Query Planning & Optimization
>            Reporter: Aman Sinha
>            Assignee: Aman Sinha
>            Priority: Major
>             Fix For: 1.16.0
>
>
> This JIRA is specific to creating histograms for numeric data types: INT, BIGINT, FLOAT4, FLOAT8  and their corresponding nullable/non-nullable versions.  Additionally, since DATE/TIME/TIMESTAMP are internally stored as longs, we should allow the same numeric type histogram creation for these data types as well. 



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