Re: array_agg + limit

2010/11/27 Lew <noone(at)lewscanon(dot)com>:
> Emanuel Calvo Franco wrote:
>>
>> I'm having this 'issue':
>>
>> coches=# select array_agg(patente order by fecha desc) from
>> dia4.infraccion limit 6;
>>
>>                                array_agg
>> --------------------------------------------------------------------------
>> -----------------------------------------------------------------
>> --------------------------------------------------------------------------
>>
>>  {565538,726668,639414,739391,674212,941061,636533,981958,999057,743729,548494,923939,841427,454574,363754,670514,566266,251071,852043,1537
>> 11,952549,129124,446671,476345,168905,308274,404812,501024,738098,636071}
>> (1 row)
>>
>> I now [know] why it happens an[d] how [to] avoid it, but.... it's ok?
>> Must work like this?
>

;) Thks

> Yes and yes.  LIMIT applies to the number of rows, and that's how it's
> documented.
> <http://www.postgresql.org/docs/9.0/interactive/queries-limit.html>
>
> --

You understood me. The form proposed by Guillaume:

SELECT array_agg(patente ORDER BY fecha DESC)
FROM
(SELECT * FROM dia4.infraccion ORDER BY fecha DESC LIMIT 6) tmp;

Is the way i've talked about. My question was about the 'how it works'.

Regards,

--
              Emanuel Calvo Franco
        DBA | www.emanuelcalvofranco.com.ar
Curso a distancia Nivel 1 Admin Postgres:
    http://www.postgresql-es.org/node/525