edmondop commented on issue #10102:
URL: https://github.com/apache/datafusion/issues/10102#issuecomment-2113997737
I want to create a udf that can select multiple functions at once, such as a
COLUMNS(<regex>) function.
```sql
select COLUMNS('number\d+') from my_table.
```
however, looking at the struct UDF, it seems that it only receives the
columns that are passed to function invocation and doesn't have access to other
columns, i.e. in the `struct` udf, all columns are returned as a struct, which
suggests that the engine only pass a subset of the available columns
However, in the case of COLUMNS('number\d+'), you need to have all the
columns, and only return few of them from the function. In my understanding
neither `udf` nor `udaf` or `udwf` from what I have seen. We would need maybe a
fourth type of udf something like `udgf` which is invoked on all the columns of
a logical plan?
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