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

[Rémi Cura <remi.cura@xxxxxxxxx>]

Ok,

thank you Tom for this precise answer !

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?

Cheers,

Rémi-C

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

=?UTF-8?Q?R=C3=A9mi_Cura?= <remi.cura@xxxxxxxxx> writes:
> I'm interested in the tree structure inherent to the gist indexing.
> I was thinking to retrieve it from order of index.

How?  A SQL query would have no idea where the index page boundaries were
in the sequence of retrieved tuples.

> Do you know how I could access it directly?

I don't think there's any way to do that without modifying the GiST code.
What you really care about here is the contents of the upper index levels,
which is something that's not exposed at all outside the index AM.

                        regards, tom lane