Re: Querying distinct values from a large table

Alvaro Herrera <alvherre@commandprompt.com> writes:
> Gregory Stark wrote:
>> (Incidentally I'm not sure where 2-5x comes from. It's entirely dependant on
>> your data distribution. It's not hard to come up with distributions where it's
>> 1000x as fast and others where there's no speed difference.)

> So the figure is really "1-1000x"?  I bet this one is more impressive in
> PHB terms.

Luke has a bad habit of quoting numbers that are obviously derived from
narrow benchmarking scenarios as Universal Truths, rather than providing
the context they were derived in.  I wish he'd stop doing that...

            regards, tom lane