How can I use the posexplode_outer function to unnest an array and number the positions in Databricks SQL Databricks Runtime 12.2 LTS and above?
To use the `posexplode_outer` function to unnest an array and number the positions in Databricks SQL Databricks Runtime 12.2 LTS and above, you can use the following syntax:

```sql
SELECT pos, col FROM posexplode_outer(array(10, 20));
```

In this example, `array(10, 20)` is the array that you want to unnest. The `posexplode_outer` function returns a table with two columns: `pos` and `col`. The `pos` column contains the position of each element in the array, and the `col` column contains the corresponding element.

You can replace `array(10, 20)` with any array expression that you want to unnest. For example, if you have a column named `my_array` in a table named `my_table`, you can use the following query to unnest the array and number the positions:

```sql
SELECT pos, col FROM posexplode_outer(my_table.my_array);
```

Note that the `posexplode_outer` function can also be used with map expressions. In this case, the function returns a table with three columns: `pos`, `key`, and `value`. The `pos` column contains the position of each key-value pair in the map, the `key` column contains the key, and the `value` column contains the corresponding value.