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Thread: Re: GiST indeices on range types

Re: GiST indeices on range types

From
Rebecca Zahra
Date:
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? 

Thanks a lot for your time. Greatly appreciate
Rebecca

Re: GiST indeices on range types

From
Magnus Hagander
Date:
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/

Re: GiST indeices on range types

From
Rémi Cura
Date:
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>:
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. 

--