alamb opened a new issue, #17590:
URL: https://github.com/apache/datafusion/issues/17590
### Is your feature request related to a problem or challenge?
### Is your feature request related to a problem or challenge?
One form of Case statements look like
```sql
CASE
WHEN <expr> THEN <expr>
WHEN <expr> THEN <expr>
...
ELSE
END
```
As suggested by @geoffreyclaude in
https://github.com/apache/datafusion/issues/17448#issuecomment-3293549174
Any `WHEN false` will never execute and thus can be removed from the
For example
```sql
CASE
WHEN false THEN 1 -- never executed
ELSE 2
END
```
Could be simplified to
```sql
2
```
Likewise
```sql
CASE
WHEN x=y THEN 1
WHEN false THEN 2 -- never executed
ELSE 3
END
```
Could be simplified to
```sql
CASE
WHEN x=y THEN 1
ELSE 3
END
```
### Describe the solution you'd like
I would like to implement the simplification above
### Describe alternatives you've considered
I think we can just extend the existing rules for CASE simplification here:
https://github.com/apache/datafusion/blob/ec4413e7d7b41c381c98eda909e5ab650be4c5e5/datafusion/optimizer/src/simplify_expressions/expr_simplifier.rs#L1398-L1400
An example is In https://github.com/apache/datafusion/pull/17450 where
@EeshanBembi implemented a new CASE simplification
### Additional context
_No response_¯
### Describe the solution you'd like
_No response_
### Describe alternatives you've considered
_No response_
### Additional context
_No response_
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