Forum OpenACS Q&A: File storage drop and acs_sc_impl_alias_

I have RH6.2/PG7.1.3/OpenACS4.x installation. I was hoping that someone can point me in the direction or help me understand the following:

I loaded the file-storage package (CVS from 2/25). It did not work so I wanted to drop it and load a previous working version that I have. When I tried to drop it I got the following Error:

ERROR:  Function 'acs_sc_impl_alias__delete(unknown, unknown, 
unknown)' does not exist 
Unable to identify a function that satisfies the given argument types
You may need to add explicit typecasts

When I looked at acs_sc_impl_alias__delete in acs-sc-packages-create.sql I saw the following:

create function acs_sc_impl_alias__delete(varchar,varchar)
  returns integer as '
  declare
      p_impl_contract_name        alias for $1;
      p_impl_name                 alias for $2;
      p_impl_operation_name       alias for $3;
      v_impl_id                   integer;
  begin

      v_impl_id := acs_sc_impl__get_id(p_impl_name);

      delete from acs_sc_impl_aliases 
      where impl_contract_name = p_impl_contract_name 
      and impl_name = p_impl_name
      and impl_operation_name = p_impl_operation_name;

      return v_impl_id;

  end;' language 'plpgsql';

When looking at file-storage-sc-drop.sql it has drops like:

select acs_sc_impl_alias__delete(
           'FtsContentProvider',                -- impl_contract_name
           'file_storage_object',                 -- impl_name
           'datasource'                         -- impl_operation_name
           );

Is there a reason why file-storage-sc-drop.sql sends three agruments to acs_sc_impl_alias__delete when it appears to need two?

Is there a reason why acs_sc_impl_alias__delete sends one argument to acs_sc_impl__get_id when it appears to need two?

Thank you for your help.

Forum OpenACS Q&A: File storage drop and acs_sc_impl_alias__delete