Re: Bug in CREATE FUNCTION with character type (CONFIRMED BUG)

2010/4/15 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
>> I think, so RETURNS TABLE can be modified for returning typmode
>> without significant problems - this function is called in table
>> context and I don't see any problematic use case.
>
> RETURNS TABLE is just a shorthand for some OUT parameters.  I don't
> believe it's either easy or a good idea to make it work differently
> from every other function-argument-or-result case.
>

I don't know now. It minimally have to be documented

foodmart=# create function f() returns table (a varchar(10), b
varchar(20)) as $$values('Pavel','Stehule')$$ language sql;
CREATE FUNCTION
Time: 121,506 ms
foodmart=# select * from f();
a | b
-------+---------
Pavel | Stehule
(1 row)

Time: 0,718 ms
foodmart=# create table x as select * from f();
SELECT
Time: 105,357 ms
foodmart=# \d x
Table "public.x"
Column | Type | Modifiers
--------+-------------------+-----------
a | character varying |
b | character varying |

workaround is relative simple

foodmart=# create function f() returns table (a varchar(10), b
varchar(20)) as $$values('Pavel','Stehule')$$ language sql;
CREATE FUNCTION
Time: 1,009 ms
foodmart=# create table x as select a::varchar(20), b::varchar(20)
from (select * from f()) x ;
SELECT
Time: 48,592 ms
foodmart=# \d x
Table "public.x"
Column | Type | Modifiers
--------+-----------------------+-----------
a | character varying(20) |
b | character varying(20) |

Regards
Pavel Stehule

>                        regards, tom lane
>