Stuffing six separate columns into a single array?

Hey folks,
  I'm in the middle of a database design update, mostly to undo all of
the stupid things I did in version 0.01.  :)  God knows I made enough
of them...
  I have a table with the following columns:
dns1_ptr      | inet          | default '0.0.0.0'::inetdns2_ptr      | inet          | default '0.0.0.0'::inetdns3_ptr
   | inet          | default '0.0.0.0'::inetdns4_ptr      | inet          | default '0.0.0.0'::inetdns5_ptr      | inet
        | default '0.0.0.0'::inetdns6_ptr      | inet          | default '0.0.0.0'::inet
 
  (yes, I know, I didn't know any better)
  It is being replaced by:

dns_ptr            | inet[]                   | default  ...etc
  (hopefully this is more intelligent)
  Now, as I migrate the data from the old table to the new, is there
any way to just do the typical 'INSERT INTO blah SELECT a,b,c FROM blah2'
type of thing?  ie,

INSERT INTO new_table ( dns_ptr ) SELECT dns1_ptr, dns2_ptr .. FROM  old_table;
  I can't seem to get the CASTing right on the SELECT statement, but
perhaps it's not even possible.  It would be nice to be able to do
this so I don't have to write yet another perl script.  I thought a
'CAST( '{dns1_ptr, dns2_ptr}' AS inet[] )' would work, but it complained
about the input syntax on dns1_ptr.  I'm learning as I go, so maybe
that's not even close to being valid.
  Any help/advice would be greatly appreciated,

Benny


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