I have a query in Postgres that needs to be ported to Impala SQL. It looks like this:

SELECT
  a.id,
  unnest(array[
    'colname1',
    'colname2',
    'colname3']) as "Column"
  unnest(array[
    a.value1,
    b.value2,
    c.value3]) as "Value"
FROM
  public.table1 a
  INNER JOIN public.table2 b on b.table2id = a.table2id
  INNER JOIN public.table3 c on c.table3id = a.table3id

Is there any way to replicate this in Impala? It doesn’t seem to support conversion to complex types on-the-fly this way. I’m experimenting with using LOAD DATA to just hard-code the string array, but I’m lost as to how to express the second array (which looks like a funky sub-SELECT?) in Impala’s complex data type paradigm.