| From: | hubert depesz lubaczewski <depesz(at)depesz(dot)com> |
|---|---|
| To: | Victor Hooi <victorhooi(at)yahoo(dot)com> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: Performance of ORDER BY RANDOM to select random rows? |
| Date: | 2013-08-08 08:55:18 |
| Message-ID: | 20130808085517.GA26014@depesz.com |
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| Thread: | |
| Lists: | pgsql-general |
On Thu, Aug 08, 2013 at 12:01:17PM +1000, Victor Hooi wrote:
> I'm just wondering if this is still the case?
Yes. Order by random() is and, most likely, will be slow. Not sure if
there is any engine that could make it fast.
> I just ran those benchmarks on my system (Postgres 9.2.4), and using ORDERY
> BY RANDOM did not seem substantially to generating random integers in
> Python and picking those out (and handling non-existent rows).
I think you accidentally a word.
depesz
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