[jira] [Created] (ARROW-10163) [Rust] [DataFusion] Allow DataFusion to cast all types supposed by Arrow cast kernel

["Andrew Lamb (Jira)" <ji...@apache.org>]

Andrew Lamb created ARROW-10163:
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             Summary: [Rust] [DataFusion] Allow DataFusion to cast all types supposed by Arrow cast kernel
                 Key: ARROW-10163
                 URL: https://issues.apache.org/jira/browse/ARROW-10163
             Project: Apache Arrow
          Issue Type: Sub-task
            Reporter: Andrew Lamb


When the  DataFusion planner inserts casts, today it relies on special logic to determine the valid coded casts. 

The actual arrow cast kernels support a much wider range of data types, and thus DataFusion is artificially limiting the casts it supports for no particularly good reason I can see.

This ticket tracks the work to remove the extra casting checking in the datafusion planner and instead simply rely on runtime check of arrow cast compute kernel

The potential  downside of this approach is that the error may be generated later in the execution process (rather than the planner), and possibly have a less specific error message, the upside is there is less code and we get several conversions immediately (like timestamp predicate casting)

I also plan to add DictionaryArray support to the casting kernels and I would like to avoid having to replicate some part of that logic in DataFusion






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