jleibs opened a new issue, #11419:
URL: https://github.com/apache/datafusion/issues/11419
### Is your feature request related to a problem or challenge?
We frequently work with tables made up of "batch" data, which is in turn
represented via structs.
For example:
```
+--------------------------------------+
| example.MyPoints |
+--------------------------------------+
| [{x: 1.0, y: 2.0}, {x: 3.0, y: 4.0}] |
| [{x: 5.0, y: 6.0}] |
+--------------------------------------+
```
I want to be able to restructure this so the inner fields of the struct
array become their own columns:
```
+------------+------------+
| X | Y |
+------------+------------+
| [1.0, 3.0] | [2.0, 4.0] |
| [5.0] | [6.0] |
+------------+------------+
```
### Describe the solution you'd like
I would like to be able to do this from SQL.
For example:
```
SELECT array_field(\"example.MyPoint\", "X") as X,
array_field(\"example.MyPoint\", "Y") FROM custom_table
```
### Describe alternatives you've considered
I've tried to come up with some way to use `unnest` to achieve this but
can't figure out how to preserve the list.
Example:
```
> CREATE TABLE example_table AS
SELECT * FROM (
VALUES
(ARRAY[NAMED_STRUCT('x', 1.0, 'y', 2.0), NAMED_STRUCT('x', 3.0, 'y',
4.0)]),
(ARRAY[NAMED_STRUCT('x', 5.0, 'y', 6.0)])
) as example_table(mypoints);
> select make_array(px) from (select p.x as px from (select unnest(mypoints)
as p from example_table));
+----------------+
| make_array(px) |
+----------------+
| [1.0] |
| [3.0] |
| [5.0] |
+----------------+
```
### Additional context
_No response_
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