Functions returning setof record -- can I use a table type as my return type hint?

Hi all.

I have a function returning setof record. The name of a table it acts on is one of its input variables, and its output
isa set of rows from that table. E.g. for simplicity, imagine it's this pointless function: 

create or replace function select_all_from(table_name text)
returns setof record as $$
declare
begin
  return query execute 'select * from ' || quote_ident(table_name);
end
$$ language 'plpgsql' stable;

When I now query this I have to do something like the following, with an 'as' clause specifying what is going to be
returned:

select column_a from select_all_from('some_table') as (column_a integer, column_b text);

When some_table has a lot of columns, this is a real pain. I see in the PG documentation that each table is also a type
ofits own. Thus I had hoped to be able to write the following instead: 

select id from select_all_from('some_table') as some_table;

However, this is rejected ('a column definition list is required for functions returning "record"').

So -- is there some other syntax or workaround that I can use to can achieve this -- i.e. to persuade PG to accept a
tabletype in lieu of a manually-recreated column definition list?  

(And if not, where might I best suggest this as a possible future enhancement?)

Many thanks for your help,
George

--
George MacKerron  |  +44 (0)20 7193 7369  |  http://personal.lse.ac.uk/mackerro/
Department of Geography & Environment, London School of Economics


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