这可以通过字符串函数来实现，比如 substr() 以及 instr() 但即使是第二部分的访问也会变得非常复杂，所以我会使用递归 CTE 它还可扩展：

with cte as (
  select descr, 1 idx, 
         substr(descr, 1, instr(descr, ' ') - 1) leftpart,
         substr(descr, instr(descr, ' ') + 1) rightpart
  from (select description || ' ' descr from tablename)
  union all
  select descr, idx + 1, 
         substr(rightpart, 1, instr(rightpart, ' ') - 1),
         substr(rightpart, instr(rightpart, ' ') + 1)
  from cte
  where idx < 3 
)
select 
  max(case when idx = 1 then leftpart end) Description_1,
  max(case when idx = 2 then leftpart end) Description_2,
  max(case when idx = 3 then substr(leftpart, 1, 1) end) Description_3
from cte
group by descr
order by descr, idx

请看演示。
结果：

| Description_1 | Description_2 | Description_3 |
| ------------- | ------------- | ------------- |
| D             | FX            | D             |
| DX            | SVFO          | F             |
| FCS           | DFT           | D             |