Re: GiST indeices on range types

On Sat, Mar 28, 2015 at 7:52 AM, Rebecca Zahra <rebeccazahra@gmail.com>
wrote:

Good morning,

I am Rebecca Zahra and I am currently in my final year of Masters studies
at the University of Malta. My thesis is about the usage of indexes for
multi-dimensional data.

I was going through the posts regarding GIST indexes and I came across the
following
http://dba.stackexchange.com/questions/39589/optimizing-queries-on-a-range-of-timestamps-two-columns

I was wondering if maybe you can help me with a question. I know that an
R-Tree index implementation is used on top of GIST to index spatial data.
Can you please tell me what type of index is used on top of GIST to index *range
types*?

PostgreSQL has had indexable range types for quite some time now:
http://www.postgresql.org/docs/current/static/rangetypes.html#RANGETYPES-GIST

Indexable with gist or spgist. I don't think the docs cover the actual
implementation internals though - you'll probably have to go to the source
if you need that.

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/

As far as I understand it (not much), gist index over spatial data is in
fact gist index over range(x), range(y).

This is why Gist works in n-dimension. It always works on range
(conceptually).

In fact rectangle are the intersection of a range on x and a range on y
(literally)
same, a 3D box is the intersection of range on x,y,z
You could go further by adding time, etc.

Cheers,
Rémi-C

2015-04-01 9:00 GMT+02:00 Magnus Hagander <magnus@hagander.net>: