Re: randomized order in select?

Bruno Wolff III <bruno@wolff.to> writes:
>   Enver ALTIN <enver.altin@frontsite.com.tr> wrote:
>> I wish I could do something like:
>> select tiptext from tips order by random limit 1
>> in PostgreSQL.

> You can but it won't be very efficient (for large tables) as it will generate
> a random ordering for the whole table, probably do a sort and then return the
> first record.  The only thing different you need to do is add () after random:
> select tiptext from tips order by random() limit 1

If you do need to do this for a large table, I seem to recall that
we've previously worked out reasonable ways to select a random entry
efficiently using an index.  Dig around in the mail list archives for
details.
        regards, tom lane