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https://issues.apache.org/jira/browse/DRILL-6312?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Pritesh Maker updated DRILL-6312:
---------------------------------
    Issue Type: New Feature  (was: Bug)

> Enable pushing of cast expressions to the scanner for better schema discovery.
> ------------------------------------------------------------------------------
>
>                 Key: DRILL-6312
>                 URL: https://issues.apache.org/jira/browse/DRILL-6312
>             Project: Apache Drill
>          Issue Type: New Feature
>          Components: Execution - Relational Operators, Query Planning & 
> Optimization
>    Affects Versions: 1.13.0
>            Reporter: Hanumath Rao Maduri
>            Priority: Major
>
> Drill is a schema less engine which tries to infer the schema from disparate 
> sources at the read time. Currently the scanners infer the schema for each 
> batch depending upon the data for that column in the corresponding batch. 
> This solves many uses cases but can error out when the data is too different 
> between batches like int and array[int] etc... (There are other cases as well 
> but just to give one example).
> There is also a mechanism to create a view by type casting the columns to 
> appropriate type. This solves issues in some cases but fails in many other 
> cases. This is due to the fact that cast expression is not being pushed down 
> to the scanner but staying at the project or filter etc operators up the 
> query plan.
> This JIRA is to fix this by propagating the type information embedded in the 
> cast function to the scanners so that scanners can cast the incoming data 
> appropriately.



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