Re: GIST index : order Hack : getting the order used by CLUSTER .. USING my_index

[Rémi Cura <remi.cura@xxxxxxxxx>]

Great,

thanks.

Now you say that I never saw any improvement when clustering table with gist.

You just saved me a lot of unnecessary queries :-)

Cheers,

Rémi-C

2013/10/24 Tom Lane <tgl@xxxxxxxxxxxxx>

=?UTF-8?Q?R=C3=A9mi_Cura?= <remi.cura@xxxxxxxxx> writes:
> I don't understand how the CLUSTER .. USING index command work then.
> It is supposed to rewrite on disk following index order. Does it do nothing
> for GIST index?

Nobody has ever demonstrated that CLUSTER has any value for anything
except btree indexes.  It seems likely to me that it'd actually be
counterproductive for indexes like GiST, which depend on data arriving in
random order for the highest index levels to end up well-distributed.

                        regards, tom lane