Re: BUG #6565: GEQO documentation discrepancy after 9.0 change?

On Thu, Mar 29, 2012 at 3:36 AM,  <gcottenc@gmail.com> wrote:
> The following bug has been logged on the website:
>
> Bug reference: =A0 =A0 =A06565
> Logged by: =A0 =A0 =A0 =A0 =A0Guillaume Cottenceau
> Email address: =A0 =A0 =A0gcottenc@gmail.com
> PostgreSQL version: 9.1.3
> Operating system: =A0 not relevant
> Description:
>
> 9.0 release notes contain:
>
> """
> E.8.3.1.4. GEQO
>
> Use the same random seed every time GEQO plans a query (Andres Freund)
>
> While the Genetic Query Optimizer (GEQO) still selects random plans, it n=
ow
> always selects the same random plans for identical queries, thus giving m=
ore
> consistent performance. You can modify geqo_seed to experiment with
> alternative plans.
> """
>
> However, documentation up to 9.1 (pg website) say:
>
> http://www.postgresql.org/docs/9.1/static/runtime-config-query.html#RUNTI=
ME-CONFIG-QUERY-GEQO
>
> """GEQO's searching is randomized and therefore its plans may vary
> nondeterministically."""
>
> I guess this sentence is outdated now?

Hmm, sounds like it.  Does anyone think otherwise?

--=20
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company