Re: random rows

From: "Ing(dot) Roberto Andrade Fonseca" <randrade(at)abl(dot)com(dot)mx>
To: Jie Liang <jliang(at)ipinc(dot)com>
Cc: pgsql-admin(at)postgresql(dot)org
Subject: Re: random rows
Date: 2001-04-26 18:12:14
Message-ID: Pine.LNX.4.10.10104261309480.12882-100000@inter.interservice.com.mx
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-admin pgsql-general pgsql-sql

On Thu, 26 Apr 2001, Jie Liang wrote:

>
> How I can return random N rows from my select stmt?
> like:
> e.g. what my selectee is a set of 1000 rows, I want randomly
> pickup 100 of 1000.

I've donne something like:

prereg_iw=# select random(), nombre from asistente order by 1 limit 10;
random | nombre
----------------------+---------------
0.000214523170243261 | ALFONSO
0.000478655100091666 | OSCAR
0.000892118085591177 | JOSE LUIS
0.000972398091560415 | IGNACIO
0.00109919300354048 | NORBERTO
0.00180558208460248 | SALVADOR
0.00196880800741204 | ANDRES NOE
0.00197171233686233 | SARA MICHELLE
0.00226354412839913 | DAVID
0.00233715307076329 | RODOLFO
(10 rows)

and it works!

Saludos,

Roberto Andrade Fonseca
randrade(at)abl(dot)com(dot)mx

In response to

Responses

Browse pgsql-admin by date

  From Date Subject
Next Message Jie Liang 2001-04-26 18:38:21 random rows
Previous Message Josh Berkus 2001-04-26 17:42:54 No JOINs in UPDATE ... FROM?

Browse pgsql-general by date

  From Date Subject
Next Message solo 2001-04-26 18:25:15 Problem connecting to postgres
Previous Message Jeff Eckermann 2001-04-26 18:10:31 RE: Data Export from PostGreSQL

Browse pgsql-sql by date

  From Date Subject
Next Message Jie Liang 2001-04-26 18:38:21 random rows
Previous Message Josh Berkus 2001-04-26 17:42:54 No JOINs in UPDATE ... FROM?