"symlink" data to new database
You can achieve something like this using a federated view. After configuring the federated data source as described in the manual, you would create a nickname for the archive table

CREATE NICKNAME Archive_Prod FOR archive_server.archive_schema.Archive_Prod;


After that you would create a view joining the two tables:

CREATE VIEW v_active_prod AS 
  SELECT local.aliasapptype, local.aliasappreason, local.pzinskey, remote.pzpvstream
  FROM Active_Prod local
  INNER JOIN Archive_Prod remote
  ON (local.aliasapptype, local.aliasappreason, local.pzinskey) 
   = (remote.aliasapptype, remote.aliasappreason, remote.pzinskey)


assuming aliasapptype, aliasappreason, pzinskey is your primary key.

If you want to fetch your BLOBs regardless of where they reside, you may want to choose an outer join instead:

CREATE VIEW v_active_prod AS 
  SELECT local.aliasapptype, local.aliasappreason, local.pzinskey, 
         COALESCE(local.pzpvstream, remote.pzpvstream)
  FROM Active_Prod local
  LEFT JOIN Archive_Prod remote
  ON (local.aliasapptype, local.aliasappreason, local.pzinskey) 
   = (remote.aliasapptype, remote.aliasappreason, remote.pzinskey)


Don't expect performance to be stellar though when reading BLOBs from a federated data source.