> -----Original Message----- > From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general- > owner@xxxxxxxxxxxxxx] On Behalf Of piotr_sobolewski > Sent: Thursday, November 01, 2007 9:25 AM > To: pgsql-general@xxxxxxxxxxxxxx > Subject: select random order by random > > Dear sirs, > > I was very surprised when I executed such SQL query (under PostgreSQL > 8.2): > select random() from generate_series(1, 10) order by random(); > > I thought I would receive ten random numbers in random order. But I > received > ten random numbers sorted numerically: > random > ------------------- > 0.102324520237744 > 0.17704638838768 > 0.533014383167028 > 0.60182224214077 > 0.644065519794822 > 0.750732169486582 > 0.821376844774932 > 0.88221683120355 > 0.889879426918924 > 0.924697323236614 > (10 rows) > > I don't understand - why the result is like that? It seems like in each > row > both random()s were giving the same result. Why is it like that? What > caused > it? > > -- > Piotr Sobolewski > http://www.piotrsobolewski.w.pl > > > ---------------------------(end of broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will ignore your desire to > choose an index scan if your joining column's datatypes do not > match [Lee Keel] Would this not have to do with the 'order by' you added to the end of the statement? If you remove the order by clause, then it works for me... -LK This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the sender. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
