Re: PL/pgSQL: How to return two columns and multiple rows

On Thu, Jun 18, 2015 at 9:52 AM, Sven Geggus <lists(at)fuchsschwanzdomain(dot)de>
wrote:

> Raymond O'Donnell <rod(at)iol(dot)ie> wrote:
>
> >> mydb=> select myfunc('foo','bar');
> >
> > You need to do:
> >
> > select * from myfunc('foo','bar');
>
> This has been a misguided example. Reality should more likely look like
> this:
>
> select myfunc(col1,col2) from mytable;
>
> And it would of course be undesired if myfunc would be called twice per
> row.
> So how would this look like to avoid the function beeing called twice?
>

​WITH exec_func AS ( SELECT myfunc(col1,col2) FROM mytable )
SELECT (exec_func.myfunc).* FROM exec_func;

This relies on the fact that currently a CTE introduces an optimization
barrier.

David J.
​