alamb commented on issue #1818:
URL:
https://github.com/apache/arrow-datafusion/issues/1818#issuecomment-1039599084
Nice find @xudong963
> Currently, DF judges if the logical plans in union have the same schema by
arrow schema's field name
This sounds like the problem to me -- perhaps we need to add a special "does
this schema match for the purposes of union" type check 🤔
Another thought I had would be to add `LogicalPlan::Projection` to map the
names of union inputs to be compatible (assuming that the types are the same).
Something like this perhaps:
Plan now;
```text
Union --> results in error because `x` not the same as `a` and `y` not the
same as `b`
... original input for (x,y)
... original input for (a, b)
```
use a `Projection` to remap the names:
```text
Union
Projection(x as "column1", y as "column2")
... original input for (x,y)
Projection(a as "column1", b as "column2")
... original input for (a, b)
```
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