Re: 4.2.9. Type Casts - documentation improvement

> On Sep 12, 2017, at 3:33 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>
> On Tue, Sep 5, 2017 at 02:17:12AM +0000, artejera(at)gmail(dot)com wrote:
>> The following documentation comment has been logged on the website:
>>
>> Page: https://www.postgresql.org/docs/9.2/static/sql-syntax.html
>> Description:
>>
>> Hi,
>>
>> There seems to be no explicit documentation of the useful construct:
>>
>> Select tt.*::text from tt
>>
>> Also related: 4.2.13. Row Constructors
>>
>> Congrats for your project. Yours AT
>
> Woh, I was not aware that worked, e.g.:
>
> test=> SELECT pg_language.*::text FROM pg_language;
> pg_language
> -------------------------------------
> (internal,10,f,f,0,0,2246,)
> (c,10,f,f,0,0,2247,)
> (sql,10,f,t,0,0,2248,)
> (plpgsql,10,t,t,12319,12320,12321,)
>
> Any idea where this should be documented. It is useful?

It's the output format of a composite type, isn't it?

steve=# select pg_language from pg_language;
pg_language
-------------------------------------
(internal,10,f,f,0,0,2246,)
(c,10,f,f,0,0,2247,)
(sql,10,f,t,0,0,2248,)
(plpgsql,10,t,t,12656,12657,12658,)
(4 rows)

https://www.postgresql.org/docs/current/static/rowtypes.html might be the place to expand on it, if so. (And converting to hstore or json or csv are other useful things to discuss too, maybe).

Cheers,
Steve